The Project Gutenberg eBook, Big Bend National Park, Texas, by Anonymous
Handbook 119 Big Bend
Big Bend National Park, Texas
Produced by the
Division of Publications
National Park Service
U.S. Department of the Interior
Washington, D.C. 1983
Using This Handbook
The major attractions at Big Bend National Park in west Texas are the Rio Grande and its canyons, the Chisos Mountains, and the Chihuahuan Desert. Part 1 of the handbook gives a brief introduction to the park and its history; Part 2 takes a close look at the area’s natural history; and Part 3 presents concise travel guide and reference materials.
National Park Handbooks, compact introductions to the great natural and historic places administered by the National Park Service, are published to support the National Park Service’s management programs at the parks and to promote understanding and enjoyment of the parks. Each is intended to be informative reading and a useful guide before, during, and after a park visit. More than 100 titles are in print. This is Handbook 119. You may purchase the handbooks through the mail by writing to Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.
Library of Congress Cataloging in Publication Data
Main entry under title:
Big Bend.
(National park handbook; 119)
Includes index.
1. Big Bend National Park (Tex.).
I. United States. National Park Service. Division of Publications.
II. Title.
III. Series: Handbook (United States. National Park Service. Division of Publications); 119.
F392.B53B49 917.64’932 82-600156 AACR2
Contents
[Part 1 Welcome to Big Bend Country] 4 [Where Rainbows Wait for Rain] 6
[Part 2 From the Rio to the Chisos] 24 Text by Helen Moss [A World of Difference] 27 [Waterholes, Springs, and the Fifth Season] 43 [As the Wild River Runs] 59 [Along the Greenbelt and Among the Grasses] 73 [Where Mountains Float in the Air] 93
[Part 3 Guide and Adviser] 110 [Map of the Park] 112 [Approaching Big Bend] 114 [Facilities and Services] 117 [Walking Trips and Hiking] 119 [Birding] 120 [Floating the River] 122 [Fishing] 123 [Tips for Desert Travelers] 124 [Park Regulations] 125 [Armchair Explorations] 126
[Index] 127
1 Welcome to Big Bend Country
Indians held that after making the Earth the Great Spirit dumped leftover rocks on the Big Bend. “The unknown land,” Spanish explorers labeled it. Its mythic topography inspired quests for lost mines and instant wealth in gold and silver. A rainbow over Cerro Castellan implies its own pot of gold.
Where Rainbows Wait for Rain
Far down on the Mexican border the Rio Grande makes a great U-turn. Inside this mighty curve lies a national park and the special and spectacular section of southwest Texas known as “Big Bend Country.” More than a century ago a Mexican cowboy described Big Bend as “Where the rainbows wait for the rain, and the big river is kept in a stone box, and water runs uphill and mountains float in the air, except at night when they go away to play with other mountains....” This land is so vast and so wild that you can feel your human smallness and frailty. Silence takes on the quality of sound, and isolation can bring you face to face with the interdependence of all life forms.
Paradox abounds. There is killing heat and freezing cold; deadly drought and flash flood; arid lowland and moist mountain woodland; and a living river winding its way across the desert.
Spanish explorers called Big Bend the “unknown land,” and for hundreds of years civilization passed it by on either side. Entrenched behind deep river canyons and walled in by rough and rugged mountains, this vast country remains today a world apart. Fewer than 13,000 people occupy an area about the size of Maryland, mostly in two or three towns strung along the highway to the north. Only three paved roads run south into Big Bend, and whatever route you take, you’ll find yourself in country that looks less and less familiar the farther you penetrate it. Here are the landscapes, plants, and animals typical of the Chihuahuan Desert, a high dry wilderness that spills northward out of Mexico into far west Texas and southern New Mexico.
Basically, Big Bend’s desert is a rolling land of creosotebush and bunch grass. But it grows gorgeous forests of giant yucca and solid stands of lechuguilla, a barbed and bladed plant found only in the Chihuahuan Desert. Big Bend’s desert has living sand dunes, painted badlands, and petrified trees, and since it is a geologically young desert, its landforms stand in rugged relief. Igneous dikes march across plain and mountain like so many man-made stone walls. Chimney-tall stacks thrust up from barren flats as from a ruin. Volcanic ash heaps, white as snow, lean their concrete shoulders against maroon hills.
The Indians used to say that after making the Earth, the Great Spirit dumped the leftover rocks on Big Bend. Heaped up, scattered wide, and piled into mountains, they lie here to this day. Since vegetation is so scant, Big Bend mountains take their shape and color from the rocks of which they are made. They loom castellated, cathedral-domed, flattopped, and razor-backed. They look red, yellow, gray, black, white, and all the shades of brown, empurpled by distance or misted over after rain in a gauzy film of green. You don’t know which is more awe-inspiring, looking up or looking down, since the mountains rise with striking suddenness between the vaulted sky and the open plain. Approaching the Chisos Mountains for the first time, you can’t believe that cars can breach those bastions, or that high inside there actually is a Basin where travelers have camped since people first gazed on these mountains. Undulating foothills fling themselves like breakers against the sheer rock cliffs. Standing atop the escarpment that walls up the Chisos South Rim, you see hills and mountains rolling like ocean waves far, far below, with here and there a gleam of silver where the river runs.
Big Bend’s Rio Grande takes its moods from the weather, the season, the time of day, and the changing nature of its bed and banks. The river runs lavender-rose at sunset, brown between frost-reddened shrubs, shining like a tin roof under hazy skies, white as chopped ice where rapids churn, olive-green beneath the brooding cliffs of Old Mexico. Nobody knows which came first, the mountains or a through-flowing river, but for hundreds of river kilometers the Rio dodges and doubles, and where it cannot go around it rasps its way across the mountains. Deep-cut canyons alternate with narrow valleys walled in by towering cliffs. You can’t get across except at a handful of fords, or up steep trails at favorable stages of water. These canyons and escarpments lend Big Bend its monumental character, for as it digs, the river lays bare millions of years of Earth history. To run a desert river canyon is to penetrate the long, tortuous corridor from everlasting to everlasting: Time is here turned to stone. Imprisoned, yet wild and free, the Rio runs the ages down inside a rock-ribbed vault.
Inside the gorgeous gorges of the Big Bend of the Rio Grande, the river’s flow determines real time. Canoeists in fast water work the Eternal Now.
Other moods abound. Changing light conditions paint Santa Elena Canyon with subdued hues (opposite), then splash it with bold and saturated colors (following).
Human beings have lived in the Big Bend area for ten to twelve thousand years. The first to come were probably nomadic hunters following the big game that drifted south ahead of the last great continental ice sheet. They hunted elephant, camel, bison, pronghorn, and horses, as indicated by their kill sites discovered in the mesa and Pecos River country to the north and east of the park. But as the Earth warmed up and glaciers melted, a deadly dryness crept eastward from Mexico’s Sierra Madre Occidental and engulfed Big Bend. Moisture-loving plants died out or were driven out by drought-resistant species, and as the climate and vegetation changed, so did the animals. Many Ice Age mammals perished forever and the hunters themselves seem to have disappeared.
Not surprisingly, the next people to infiltrate Big Bend were nomadic Indians adapted to desert life. Theirs was a follow-the-food economy, and they camped in caves and rock shelters close to such water sources as the Rio Grande and its tributaries, springs, and rock wells. They hunted desert animals for meat and skins, ate juniper berries, pricklypears, century plant hearts, yucca blossoms, and mesquite beans. They made baskets, nets, mats, and sandals from basketgrass and the long slim leaves of the yucca. Today, thousands of years later, remnants of these may still be found in dry caves. These prehistoric nomads also disappeared, perhaps killed or absorbed by the Jumanos, a semi-pueblo people who came to occupy the river valleys west of the park.
Cabeza de Vaca and his companions are thought to have been the first Spaniards to reach Big Bend. In 1535 they were astonished to find a farming people—probably the Jumanos at Presidio—living in actual houses at the junction of two rivers. Many years were to pass before the conquistadores scouted this far country. Driven by their lust for gold and silver and zealous to Christianize the Indians, the Spaniards ignored Big Bend because they thought this unpeopled desert held no riches. The only Indians then living in the park were the Chisos, a tribe from north central Mexico that passed its summers in the mountains north of the Rio Grande. The Spaniards had the habit of enslaving Indians to work their mines, and the Chisos retaliated by coming down from Big Bend to raid the Spaniards. In 1644 the Chisos won a great victory, but in the end, they were driven out by a new group of Indians who filtered down the Rio Grande from New Mexico. These were the Mescalero Apaches, so-called because they ate the heart of the “mescal” or century plant. So fierce and skilled in battle were they that even the Spaniards fled before them. By 1720 they dominated Big Bend, becoming known as Chisos Apaches. Regarding themselves as mountain folk, the Apaches became the most successful desert dwellers and guerrilla fighters this country has ever known. What nature did not provide they took by raiding. Belatedly the Spaniards tried to stop the raids by building forts near major Rio Grande fords. One of these, a combination mission and presidio, was built about 1770 on the Mexican side at the park’s San Vicente crossing. But the Apaches kept up the pressure, the Spaniards fled, and the fort soon lay in decay.
Strawberry pitaya cactus blossoms and articulated spines pose delicate counterpoints to sweeping desert, mountain, and canyon grandeur.
About this same time a new group of raiders, the Comanches, appeared in Big Bend. These nomadic buffalo hunters may have been the finest horsemen the world has ever seen. They ruled the south plains from Oklahoma to Texas and used Big Bend as a highroad to Mexico. For more than a hundred years, at the full of the September moon, the painted warriors crossed the Pecos and swept down past the flattopped hills and on up the long, empty, gently sloping desert floor toward the blue mountains, threading the Santiagos at Persimmon Gap where U.S. 385 now enters the park. They forded the Rio Grande at present-day Lajitas, picked Mexico clean as far south as Durango, and turned home at the end of the year. Driving captives and herds of horses and cattle northward, they probably recrossed the Rio at Paso de Chisos just to the west of Mariscal Canyon. We are told that for decades after the last Comanche left Big Bend, the great War Trail burned like a white scar across the landscape, scuffed bare by countless hooves.
Distinctive pads of pricklypear cactus make this most ubiquitous of cactuses readily recognizable across its extensive range, which encompasses Southwest deserts and the Potomac River banks near Washington, D.C.
Anglo-Americans took no interest in Big Bend until the Mexican War of 1848 fixed the border along the Rio Grande. In the 1850s, two U.S. Boundary Survey teams traveled downriver by boat and mule train, and their published reports give the first scientific look at Big Bend country and its plants and wildlife. But for the next quarter-century Big Bend belonged to the Indians, and to the U.S. troopers who pushed endless patrols across its everlasting wilderness, facing sun, thirst, alkali dust, danger, and sometimes death, for $13 a month. The Mescaleros knew the country. They knew how to use its mountains, caves, canyons, and arroyos, and where to find water, wood, grass, and game. But tracked at last into their most secret and remote retreats, nothing remained for them but the reservation. As for the Chisos Apaches, they were tricked into Mexico by a promise of asylum, only to be captured and killed or dispersed across Mexico.
Although Big Bend Indians had long used cinnabar red in their war paint and rock paintings, not until the end of the last century did commercial mining of cinnabar ore begin. To look at the ruins of Terlingua and Study Butte today, it is hard to imagine that 2,000 souls lived and worked just west of the park. Yet the Chisos Mining Company was once the world’s second largest quicksilver mine, producing 100,000 flasks of mercury between 1900 and 1941. The park’s own Mariscal Mine had a relatively short life and never really made money. All of the mines finally succumbed when the rich ore veins played out and the price of quicksilver fell. Similar fates overtook the copper, zinc, and lead mines that drew a couple thousand people to both sides of the river near present-day Boquillas. These mines were located in Mexico’s Sierra del Carmen and the ore crossed the river to the U.S. side via a steam-driven aerial tramway. Mule-drawn wagons and trucks then hauled it over the Old Ore Road to railhead at Marathon 160 kilometers (100 miles) away.
The Chisos Mountains loom as an island rising above an arid Chihuahuan Desert.
To feed the miners, Anglos and Mexicans set up irrigated farms near Boquillas, along Castolon valley, and at Terlingua Abaja. These activities took an enormous toll on Big Bend’s natural resources. Woodsmen scoured the country far and wide for timber for buildings and for firing mine furnaces. Ore train mules fed heavily on the chino grama grass. And when the mines failed and the farmers abandoned their fields, they left the land so bare that much time went by before the desert shrubs began taking over.
Ranching did not really come to Big Bend until after the Indian Wars. But once surveying parties began to locate and survey sections, cattle, sheep, goats, and horses came by trail and rail to feed upon the virgin grasslands. First-comers took up lands with permanent water; from the earliest days ranchmen headquartered at Oak Spring in the Chisos. Later arrivals had to dig wells and install windmills as Sam Nail did at the Old Ranch. The 1930s saw the end of “open range” ranching, and fencing became a prime concern for such ranchers as the Burnhams at Government Spring and Homer Wilson in the Chisos. Other ever-present problems involved water resources, drought, livestock losses from disease and predators, and remoteness from markets, schools, and doctors. Most ranchers understood the land and many loved it. They used their pastures to capacity, but they did not overstock the range until the 1940s. Then, just before the national park came into being, ruinous overgrazing all but wiped out the grasslands.
Today, Big Bend National Park sprawls across 3,205 square kilometers (1,252 square miles) inside the southernmost tip of the Bend. Even with interstate highways, park headquarters is a long way off. It is 660 kilometers (410 miles) from San Antonio to Panther Junction, 520 kilometers (323 miles) from El Paso, 173 kilometers (108 miles) from Alpine’s meals and motels, 110 kilometers (68 miles) from the last community, Marathon. But the journey is well worth the effort, because the park preserves some of the nation’s most dramatic land forms and rarest life forms.
The main body of the park is a great 65-kilometer (40-mile) wide trough or “sunken block” that began to subside millions of years ago, when Mesa de Anguila and Sierra del Carmen cracked off and slowly tilted up to the west and east. The Rio Grande draws the park’s southern boundary, slicing through three mountain ranges to form Santa Elena, Mariscal, and Boquillas Canyons. And right in the middle of the sunken block, rising higher than all the other mountains, the Chisos hang above the desert like a blue mirage.
Mule deer graze along the Grapevine Hills Road. As climate continues drying here, these denizens of the desert range ever higher into the Chisos Mountains, sole homeland in the United States for the Sierra del Carmen whitetail deer.
A gnarled alligator juniper suggests the timeworn landscape spread below the South Rim of the Chisos.
What makes a desert, of course, is scanty precipitation. And because of the great range in altitude—from 550 meters (1,800 feet) along the river to 2,400 meters (7,800 feet) atop the Chisos—there is a wide variation in available moisture and in temperature throughout the park. This has produced an exceptional diversity in plant and animal habitats. Receiving less than 25 centimeters (10 inches) of rainfall in a year, almost half the park is shrub desert. This plant community begins right next to the river and runs on up to about 1,050 meters (3,500 feet). Another 49 percent of the park is desert grassland, a somewhat less dry environment that you will encounter on mesa tops and foothills to about 1,700 meters (5,500 feet). From there on up, mountain canyons and slopes may sustain typical southwestern woodlands with pinyons, junipers, and oak trees. The Chisos heights receive some 46 centimeters (18 inches) of rain per year and are considerably cooler than the desert. Consequently you will even find 325 hectares (800 acres) of forest in two or three high canyons, where towering Rocky Mountain-type trees persist from cooler, moister times. And that is not all: A lush green jungle grows in a narrow belt along each bank of the Rio Grande and pushes out across the desert along creeks and arroyos. And in the river itself live creatures you wouldn’t expect to find in the middle of the desert!
Big Bend National Park is home to more than 70 species of mammals, almost as many species of reptiles and amphibians, a score or more fishes, and a fascinating host of insects and other arthropods. The wide choice of habitats makes Big Bend a birder’s paradise that offers more different resident and migrant birds than any other U.S. national park. Thanks to its location, the park marks the southernmost reach of some U.S. plant and animal species, and the northernmost reach of some Mexican species. Some plants and animals found here occur nowhere else in the world.
Since its establishment in 1944, the national park has developed programs and facilities in line with its two-fold purpose of preserving and protecting natural and historic values while also enriching the lives of its visitors. Santa Elena Canyon and historic Castolon form an important sight-seeing area in the southwestern corner of the park, and the road from Panther Junction to Santa Elena is probably the most scenic in the park. The Basin lies in the heart of the Chisos Mountains. This beautiful valley has complete motel, dining, and camping facilities, and an amphitheater where park naturalists give evening programs. The Rio Grande Village-Boquillas area on the southeast side of the park offers delightful camping, a visit to the nearby Mexican village of Boquillas, and a view of Boquillas Canyon’s magnificent portal. More than 175 kilometers (110 miles) of paved park roads link major sites and well-kept hiking, horse, and nature trails will take you to other spectacular areas. For properly equipped desert buffs, primitive backcountry roads and trails offer exciting opportunities for true wilderness adventure.
But whether you come to the park for a weekend or a week, for vistas and views, or for a close-up look at nature and its mysteries, you will find that Big Bend is more than the sum of its parts. When the setting sun paints the Sierra del Carmen red and blue and purple, you feel both Big Bend’s unity with all Earth processes and its wonderful uniqueness. In those many-colored cliffs hung above the desert, you see rainbows waiting ripe with promise for the miracle of rain.
2 From the Rio to the Chisos
Text by Helen Moss
Try to make it to the Window in the Chisos for the archetypal Big Bend sunset!
Adapting to desert dryness, creosotebushes space themselves to exploit available moisture. Their roots produce root toxins that may discourage competition from other plants.
A World of Difference
Stand on the bald knob of Emory Peak and you’ll see the Chihuahuan Desert rolled out below you with wave upon wave of mesas and mountains reaching out to the rim of the world. You can see for hundreds of kilometers in all directions. Not a house, not another human being, no living thing moves. Big Bend looks round, complete, as timeless and permanent as planet Earth itself and as beautiful and barren as the Moon. But Big Bend isn’t just one world, and it isn’t lifeless. It is many different worlds inhabited by countless creatures both great and small pursuing an extraordinary variety of lifestyles. These worlds may be as narrow as the mosquitofish’s spring-fed pool, as wide as the cougar’s hunting range, as dry as the pocket mouse’s burrow, as wet as the beaver’s pond, as open as the mule deer’s golden grassland, or as canopied as the Colima warbler’s forested canyon.
And the Big Bend world is not as changeless as it seems. Over an unthinkably long span of geologic time, and sometimes overnight, Big Bend has experienced sweeping changes that carried off whole communities of plants and animals. The great order of dinosaurs died out, and no one knows why, yet the scorpion and turtle have lived on here virtually unchanged through countless ages. Other plants and animals have staked survival on the long, slow process of adaptation to a changing environment. While one ancient lily evolved into grass, for example, another became the giant dagger we see today. Cholla cactus shades itself with thorns and the kangaroo rat manages never to take a drink.
In Big Bend as elsewhere, what animals live where is largely determined by what plants grow where. This in turn depends on such variables as the type and condition of the soil, elevation, climate, temperature, humidity, amount of cloud cover and direct sunlight, exposure to the wind, availability of water, and the drastic changes for bad and for good wrought by man. Yet there is nothing clear-cut or fixed about the edges of the different plant communities. The floodplain goes green or returns to dust depending on the river’s rise or fall. The shrub desert, the grasslands, and the woodlands all crawl uphill or down, putting out skirmishers along their lines of march. Within the national park natural forces are once again free to shape and reshape Big Bend’s different worlds. The battle seesaws back and forth between drought and ponderosa pine, tarbush and tabosa-grass, the eater and the eaten, the river and the rock, and the sun and the ageless land.
Broadly speaking there are four North American deserts: the Great Basin, Mohave, Sonoran, and Chihuahuan. The park lies within the Chihuahuan. This desert is bordered on three sides by mountains; the fourth abuts vast semi-arid plains. The Sierra Madre Oriental (East Mother Range) blocks winds from the Gulf of Mexico, except as spinoffs of summer hurricanes. The Sierra Madre Occidental (West Mother Range) blocks the westerlies. How can you recognize Chihuahuan Desert? By the lechuguilla plant (see [page 32]), which grows only in this desert.
In Big Bend you can turn back your personal clock to a time when mankind was still very obviously part of nature. You can walk in the desert and drink solitude as sweet as spring water or sit on the edge of a mountain meadow knee-deep in grass. You can watch the whitetail deer drift through the forest in a silence as perfect and ethereal as song, watching you but expressing no fear. For in the park you are just one more of nature’s creatures free to live and to grow in Big Bend’s self-healing, life-renewing world.
For many people the spirit of the desert is embodied in the vulture tirelessly circling empty skies above a bleak and barren land, the harvester of death keeping watch over desolation. But the desert is far from lifeless or the vulture wouldn’t be on patrol. The meager shrubs are miracles of adaptation and those seeming barren wastes rustle under the feet of countless busy creatures. Across the eons evolutionary selection has produced a different design for living within each species, yet all are subject to the same law.
Heat and aridity are the chief factors controlling all Chihuahuan Desert life. Most desert creatures stay in hiding during the day, keeping out of the sun in underground burrows, under rocks, or in the shrubs’ sparse shade. Many birds and most larger mammals don’t even visit the desert during the heat of the day. And although plants cannot crawl out from under the sun, nature has protected them by different means.
Probably the best way to see the living desert is to get out and walk and look. Study a plot of shrub desert in a single day and night. The most obvious desert dwellers, and sometimes the only living things you will see, are the plants. These vary from one stretch of desert to another because different species prefer different living conditions. But you will likely find plants in several categories, including woody and fibrous shrubs, cactuses, and other succulents. All have their own ways of resisting heat and drought, and all provide food or shelter to one or another special animal.
If success can be judged by sheer numbers, then the most successful desert shrub must be creosotebush, an evergreen bush that can make a living on the poorest and driest soils. You cannot mistake it for any other. The ground around it is apt to be bare and the individual bushes so evenly spaced that they look hand planted. This characteristic creosotebush pattern is probably caused by root competition for scant moisture. Each creosotebush has a long taproot reaching down maybe 9 meters (30 feet) to find underground water, while a network of shallow roots spreads far and wide to capture every drop of surface moisture. The plant protects itself from moisture loss by giving its dark green leaves a light-reflecting coat of resin. In the springtime, and often after rain, it bursts into brief yellow flower. It fruits in fuzzy little white balls, and you sometimes see a plant bearing both fruits and flowers.
Fortunately for the creosotebush, its taste is so unpleasant that few large animals care to eat it. But the little creosotebush grasshopper spends his whole life living and nibbling on the shrub. You’ll hear him chirping away in a creosotebush, but unless he jumps you may never find him. He’s a great ventriloquist who across countless generations has evolved protective coloring, the same dark green as creosote leaves, marked with the same red and white of its little stems and fruits. You may never see the mottled gray and black walking-stick insect either, who sticks his front legs straight out in front of him to look exactly like a woody creosotebush twig. Creosotebush holds the desert soil as blowing sands heap hummocks around its stems, and these make favorite burrowing sites for all sorts of little desert rodents and reptiles. Look under almost any creosotebush, and you will see their holes. You may even see a busy line of ants taking bits of creosote leaf and fruit to an underground nest.
The ocotillo also goes by the name coachwhip because it so often looks like a bunch of buggy whips stuck in the ground. However, in the springtime following a wet winter, those dead-looking stalks are adorned with green leaves and topped by brilliant red flower clusters. The ocotillo is common throughout both the Chihuahuan and Sonoran Deserts.
Another curious woody shrub resembles a sheaf of coachwhips. If you see ocotillo after rain, it will look like a green fountain. If you see it during a dry spell, you may think it is dead. Not so. Ocotillo puts on a fresh close-fitting suit of green leaves whenever it rains. Then as soil and air dry out, it sheds its leaves right down to the bare brown stems. This cuts back on the plant’s water needs. Moisture loss is further reduced by resinous cells that form the inner bark. In springtime the tip of each ocotillo wand burns with a cluster of scarlet flowers.
Cactuses have done away with leaves altogether, thus reducing their surface area and cutting down on moisture loss. Although they look dry and forbidding, inside that harsh exterior their flesh is moist and succulent. The food-making function has been taken over by the thick, green, wax-covered stems. And since the stems are also used to store water, they have ballooned into a weird and wonderful assortment of shapes and sizes. You’ll find the mound-building strawberry cactus with its mass of finger-like heads, the Texas rainbow cactus with its small group of cylindrical heads topped by bright yellow flowers, the tuber-like living rock, the dog and cane cholla, and the great sprawling pricklypear that lifts its beavertails from desert flat to mountaintop.
Cactuses come heavily armed with spines so cleverly shaped that they are called “fish-hook,” “eagle’s claw,” and “horse crippler.” These spines serve a double purpose: By building a lattice work around the stem of a cactus they shade it from the sun, and in many cases they make the cactus too prickly for animals to eat. Some animals have learned to use cactus spines for their own protection. The big, ratchet-voiced cactus wren likes to build its nest in the densely spined cholla, and the packrat often piles pricklypear pads in its nest area.
Pricklypear is the commonest cactus in the park and also the easiest to identify. Purple-tinged pricklypear is just what its name suggests, and so is the brown-spine pricklypear. Blind pricklypear looks as if it has no thorns, but if you touch one of the velvety buttons on a pad, you will pick up a fingerful of almost invisible, but highly irritating little spines. Engelmann pricklypear is the most abundant species. And to human taste its fruits are delicious, although the tiny glochids, barbed spines, can hurt the mouth. Many desert creatures eat pricklypear: Flies, bees, and butterflies come to feast at the showy blossoms; birds, coyotes, peccaries, and deer eat the reddish fruits; small rodents reach between the spines to nibble on the juicy pads. In times of drought ranchers burn off the spines and feed the pads to cattle. And people lost in the desert can do as the Indians did—peel, cut, or roast the skin off the pads and the flesh yields both food and moisture. Some pricklypears are too bitter to eat, however.
Cactuses
Fish-hook cactus
Button cactus
Strawberry pitaya
Claret cup
Cholla
Pricklypear
Eagle’s claw
Rainbow cactus
Coarse strong fibers of the lechuguilla plant (top) were extracted by machine (bottom) for use in matting, ropes, bags, and household items.
The candelilla or wax plant (middle) has been used in manufacturing waxes, polishes, chewing gum, phonograph records, and candles. In the rainy season the stem fills with milky sap. In the dry season this sap coats the stem as wax by evaporation. The wax protects the plant from drought.
One of the most interesting plants in the Chihuahuan Desert is a sturdy bunch of blades called lechuguilla. This fiercely spined agave lives nowhere else in the world. When Cabeza de Vaca crossed Big Bend in 1535, the lechuguilla grew so thick that he didn’t dare walk at night. Today you find it growing singly or in colonies from the shrub desert clear up into the Chisos woodlands, its needle points still menacing hikers, horses, and deer.
Lechuguilla is a fiber plant that keeps its juicy parts underground until it blooms, which it does only once a lifetime, after ten to fifteen years. The bloom stalk shoots up like a giant asparagus spear maybe four meters (15 feet) tall, flowering from the bottom up in close-packed purplish or yellowish blooms. Then the whole plant perishes by degrees. You may find a lechuguilla whose blades have died and dried while the bloomstalk is still moist and green. Eventually the bloomstalk, too, will turn into wood strong enough for a deer to lean against when rubbing velvet from his antlers.
Lechuguilla reproduces both by seeds and by rhizomes, and you sometimes find tiny new rosettes breaking ground on the runners of a mature plant. Peccaries often root up the juicy lechuguilla rhizomes, while mule deer relish the tender bloomstalk, munching it much as a cow chews a stalk of corn. Pocket gophers eat the core right out of a standing plant by tunneling underground.
The kinds of animals you meet in the desert will differ with the time of day and the time of year. They must find food and moisture, mate, and raise their young without exposing themselves to killing heat and the risk of dehydration. Insects, spiders, scorpions, and reptiles all derive their body temperature from their surroundings. This is why they stiffen up to the point of helplessness when it’s cold, and why crawling on a super-hot surface will kill them in short order. Their temperature regulation problems are compounded by conditions in the desert, and most of them cope by modifying their behavior.
In the early morning you may see grasshoppers sunning themselves on a rock as rattlesnakes will do. They line up broadside to the sun’s rays, raising their wings and lowering their legs to expose their abdomens directly to the sun’s warmth. By noonday they line up parallel to the sun’s rays to minimize heat absorption, and they will seek shade. Also, instead of hopping over the ground, many Big Bend grasshoppers live in and fly from bush to bush. The surface of the desert may be 20 to 25 degrees Celsius (40 to 50°F) hotter than is the air just over a meter (4 feet) above the ground. This is why in the daytime you will mostly see only flying insects, such as butterflies, grasshoppers, true bugs, true flies, and bees, and why so many crawling insects stay hidden during the heat of the day. However, there are some curious exceptions: The darkling beetle scurries about over the sand throughout the day. An air-filled space under its hard outer wing-covers acts as a kind of insulation between the back and abdomen. Some darkling beetles also raise the abdomen at an angle of about 45 degrees. Speed is of the essence for this little scavenger as it scurries from cover to shade.
Some grasshoppers are ground dwellers that have lived on the desert pavement so long that they even look like stones. Many come in conventional grasshopper shape but are mottled in shades of gray and mauve. The toadhopper that inhabits wash bottoms and rocky areas has taken on the color, shape, and texture of rock. Fat and squatty, he will camouflage himself, tucking his antenna right down in front of his face and pulling his legs in close to his body. You can’t even see him when you know he is there. By comparison, the lubber grasshopper advertises his presence. He is a large black beast gaudily marked in coral-snake red and yellow. Apparently these colors warn predators that the lubber is distasteful. He is out and about from late morning on.
Whiptail scorpions, which are not true scorpions, have no stinger. They pursue insects and other invertebrates and kill them with powerful pincers.
Eleven species of stinging scorpions live in the park. Coloration varies from dull-cream through brown to shiny black.
Also seen in broad daylight is the worm-like millipede rippling its way across the desert pavement. This maroon-colored plant eater has up to 200 legs arranged in short double pairs along a 13-centimeter (5-inch), many-segmented body. He isn’t poisonous and won’t sting or bite, but he may emit a substance lethal enough to kill other insects in a confined area.
Of course, the chief daily events of life in the desert are eating and being eaten, and predators that favor a certain diet make it their business to be out when their kind of dinner is around. Thus the grasshopper-eating lizards brave the daytime heat to do their hunting. Most often seen is the quick moving western whiptail. The greenish collared lizard may be seen racing along on his hind legs like a miniature dinosaur. Lizards are about the biggest ground dwellers you scare up on a noonday walk—unless you happen on a lizard-eater like the big, pink western coachwhip snake.
At twilight you become most aware of the desert’s residents. The coolness brings them out. Some must hurry and eat before it gets full dark, while others have the whole night ahead of them. At first you may sense the desert’s coming-to-life more by listening than by looking. You hear the lesser nighthawk trilling like a toad. Then, without warning, the whole desert begins to sing, as katydids, grasshoppers, and crickets join in a tapestry of sound so rich you can almost touch it.
Soon the desert cottontail creeps from his thicket to nibble pricklypear fruit. He stays close to home and prefers brushy terrain. The blacktailed jackrabbit passes the day in a form, a basin scratched out beneath some bush. He can cover the ground in enormous jumps, and his megaphone ears help cool him by dissipating body heat. The desert mule deer, another blacktailed, long-eared browser, may also appear at dusk to forage mesquite and lechuguilla. And a band of peccaries—or javelinas as they are also called—may rattle through the brush. They have a great fondness for pricklypear and their mouths are so tough they eat roots, fruits, pads, spines, and all. The ferocity of these wild pig relatives is more fiction than fact. If you meet one face to face, he may take a few steps toward you, but not out of meanness. He’s nearsighted!
Evening can linger a long time in the desert and night can strike quickly as a cat’s paw. You watch the sun go down, turning the clouds above the Chisos red, painting Sierra del Carmen crimson, while a single golden shaft breaks through the clouds and hits El Pico like a spotlight. Then the sky goes smoky blue and mauve over the eastern mountains, and the clouds to the west turn ashen as burned out coals.
Lizards
Collared lizard (male)
Texas banded gecko (adult)
Texas alligator lizard
Twin-spotted spiny lizard
Collared lizard (pregnant female)
Texas banded gecko (young)
Marbled whiptail
Big Bend gecko
Snakes
Western hognose snake
Mexican milk snake
Blacktail rattlesnake
Trans-Pecos blind snake
Western coachwhip snake
Trans-Pecos rat snake
Western diamondback rattlesnake
Blackneck garter snake
Baird’s rat snake
Big Bend patchnose snake
Texas lyre snake
Glossy snake
Mohave rattlesnake
Longnose snake
Black-hooded snake
Bullsnake
Two Non-Drinkers
The kangaroo rat and roadrunner exemplify adaptations for desert living. Neither drinks water, as a rule. The roadrunner gets its moisture largely from its omnivorous diet, which includes lizards and small rattlesnakes. It kills them with stunning blows of its beak. Its characteristic X-track provides good traction in sand. Agile and nimble, this 60-centimeter- (2-foot) long bird can fly, but it prefers to run, at up to 32 kph (20 mph). Mexicans call the roadrunner paisano, “fellow countryman.”
The kangaroo rat metabolizes both energy and moisture from seeds that contain less than 4 percent water. It has no sweat glands and cools itself by breathing. Its nasal passages, cooler than the rest of its body, condense breath moisture for retention. Its kidneys, among the most efficient in the animal world, excrete uric wastes as a concentrated paste, not as liquid, saving further precious water. Its deep burrow has a year-round relative humidity between 30 and 50 percent. These rodents sometimes fight with each other, leaping high into the air and striking at each other with their strong hind legs.
You can see the nighthawk now against the pale and pearly afterlight, and a star pops out, then another and another. Suddenly, more stars seem to be twinkling than can possibly exist in the universe. In the absence of man-made light they are an overwhelming presence. The Milky Way stretches from horizon to horizon. Who can believe that our Sun is just a middle-sized star, and planet Earth a mere speck spinning on the fringes of that gorgeous luminosity?
On a night of no moon, in the mist of starlight, the mule deer may stay active until dawn. On mild, windless nights the hunters and the hunted come out in full force: insect-eating scorpions, tarantulas, and wolf spiders; seed-eating pocket mice and kangaroo rats; rodent-eating snakes, badgers, and owls. What a hurrying and scurrying, what popping up from holes and burrows, what slithering and digging, what squeaks and shrieks, what patient waiting in ambush. And by what ingenious means do the hunters find the hunted in the dark! Beep-beeping bats locate insects and avoid obstacles by bouncing sound waves, imperceptible to humans, off objects as they fly. The female katydid wears her ears on her knees; by waving her front legs she zeroes in on the male’s mating call. Cold-blooded rattlers heat-sense warm-blooded rats and mice. And just as an astronomer opens the aperture on his telescope, so the owl at night widens his enormous eyes for light from far off stars.
Toward dawn the morning star burns like a lamp in the east, and gradually, a pale flush spreads upward from the crest of the Sierra del Carmen. A bank of clouds hangs off the Fronteriza, and as the overhead stars wink out and the morning star burns on, the pale glow turns peach and seeps higher. Just enough air stirs to shake the mesquite. A waking bird emits one cluck. Soon the clouds below the Fronteriza go salmon pink and flare with internal fire. As the sun tops the Sierra del Carmen and spills a glare sharp as ice shards over the desert, you hear a distant bark. One yap, two, a soprano howl, an alto tremulo, then chord upon chord in wild and worshipful sounding chorus. Somewhere in the ruddy hills a pack of coyotes seems to sing the sun up.
Desert flowering plants adorn a mudflat almost as metaphors of patience. The secret lies with seeds that have adapted to remain dormant for years, if necessary, until enough rain falls to bypass their germination inhibitors.
When rains raise the water level, animals drink from natural tanks such as Ernst Tinaja. Tinajas can also be death traps when the water level falls so low that animals can’t climb back out. Mountain lion claws have etched desperation into the rims of some.
Waterholes, Springs, and the Fifth Season
One of the most astonishing sounds in the desert is that of trickling water. One of the happiest desert sights is a pool dancing with aquatic creatures. Who can believe it: Tadpoles darting about, water striders dimpling the surface, blue darners stitching zig-zags through the air and dipping the tips of their abdomens into the water? What a celebration of life in the midst of apparent lifelessness.
Water is the single most important need of almost all life forms in the desert. The larger mammals, many birds, and some insects must drink daily to survive. Some amphibians and arthropods must spend at least part of their lives in the water. Each waterhole is a little oasis supporting its community of plants and animals, and drawing from the outside world a thirsty parade of creatures that comes to it to sustain life.
Apart from the river, there are at least 180 springs, seeps, and wells in the park that serve as wildlife watering places. Most of these are springs located within the grasslands on the lower slopes of the Chisos Mountains. Springs differ greatly, ranging from a seep with 0.5 centimeters (0.25 inches) of water standing in the grass, to a 25-centimeter (10-inch) deep pool the size of a table top, to a string of pools connected by a flowing stream. Since springs depend for their flow on water seeping through the ground, and since this in turn depends on rainfall, the amount of water found at a spring may vary greatly from season to season and from year to year. Other crucial factors are evaporation and the water consumption and retention properties of the spring’s plant life.
You can see most springs a long way off. They stand out like timbered islands in an ocean, with tall cottonwoods, willows, and honey mesquite, and man-high thickets of thorny acacia festooned in silver showers of virgin’s bower. Dozens of little rodent holes perforate the ground among the roots and the tall grasses quiver with furtive comings and goings. Life at such a spring follows a regular pattern from dawn to dusk, although it may actually be busiest at night when most desert creatures are abroad.
At first daylight four or five redheaded turkey vultures stir in the cottonwoods where they have spent the night. They shrug their black shoulders and wait for the sun and the thermals to rise. An early blacktailed gnatcatcher chases a late moth, but the moth proves the better acrobat and makes it to safety in the thicket. Doves leave the ground with a flutter of white-barred wings and level off across the desert. By following the game trails to water, you can read the sign of nighttime visitors: The cloven-hoofed track of peccaries imprinted in the ooze, cigar-shaped coyote scat complete with fur, the flat-footed print of a striped skunk, and the larger cloven hoofprints of mule deer.
Desert amphibians? Leopard frogs live along the river and near ponds and springs.
Couch’s spadefoot toad evades drought by burrowing with specially adapted hind feet (bottom). When rains come, the toads move to the nearest puddle and mate. Their eggs hatch six times faster than those of garden toads and the tadpoles quadruple their birth weight by the second evening of life. With luck some mature before the puddle evaporates—and dig in to await another wet spell.
Soon it is full morning with flies biting, lizards scuttling, and butterflies feeding in jackass clover. By noonday a brisk breeze is shaking the cottonwood leaves, producing a sound like rushing water, and two ravens have come to croak in a little mesquite. Now they fly, with the sun striking silver from jet feathers. They circle the oasis, flapping and soaring, driving their shadows below them over the ground.
Here on a willow trunk is a life-and-death contest. Rubbed raw by the branch of a neighboring tree, the willow is exuding sap from a saucer-sized wound. Drawn to the sap, six butterflies stand on the damp spot peacefully feeding, slowly opening and closing their wings. All at once a mantidfly pounces from ambush and grabs at a butterfly with his clawed front legs. The butterfly leaps like a scared horse, and in reaction the whole group takes to the air. But in a moment they settle back down, roll out their tongues like party toys, and begin to sip. Another fierce lunge by the mantidfly, another scattering of butterflies. And all the time you can hear the tick-tick-tick of a beetle boring a burrow in the diseased wood.
As evening comes on, the doves come in from the desert, flying low along the line of seepage. The vultures return to roost, lazily circling the cottonwood’s crown. While it is still light the butterflies seek cover in the cottonwood leaves. As it gets dark the moths come out, and after them the bats, beep-beeping as they cut erratic patterns through the dusky air. Soon the breeze will die down, and the starlit night will throb with the long drawn trill of tree crickets. In the wee small hours there will be no sound, no breath of air or outward sign of life. Then suddenly along a sandy trail moves a blackness shaped like a high-backed child’s chair. It is a striped skunk, tail-high, come to take its turn at the waterhole.
The javelina, or peccary, smells like a skunk. This nighttime wanderer uses the scent for territorial marking, not defense. Curious and shortsighted, javelinas might approach a hiker—not to attack, but to investigate.
Few and far between are the springs with sufficient flow to send a brook singing down a ravine. But such a place is Glenn Spring, the chief spring along a dry draw that starts in the Chisos and cuts deeply through many-colored clays as it crosses the desert. Historic photos show Glenn Spring enclosed within a man-made rock wall. Today you cannot even find the source, so thick is the tangle of tules and cane grown up around it. The flow from Glenn Spring trickles down the draw about 1.5 kilometers (1 mile), collecting in pools and gurgling over rocks before it goes underground. Some of the pools are crystal clear, and some are black with the acids of plant decay. Deeper pools are fern-green with algae. Little black snails harvest algae on the rocks and leopard frogs croak and plop, so quick to hide among the reeds that you can hardly find them. These slim, spotted amphibians, insect feeders, mate in water. Their larval young, free-swimming tadpoles, must live in water, feeding on microscopic organisms until they grow lungs and legs for life ashore.
The tadpole itself falls prey to giant water bugs, air-breathing water dwellers that are also strong fliers. The water boatman is a vegetarian who sculls about from one underwater plant to another. You can hardly tell him from the backswimmer except that the latter swings his oars upside down and spends much time on the surface hanging head down, the better to spy the aquatic insects upon which he feeds. The water strider is another hunter, but this spider-legged semi-aquatic skates atop the water, seeking terrestrial insects that have dropped onto the surface. Just as the birds and bats eat different foods at different feeding levels, so do the creatures that inhabit a pool, be it only centimeters deep.
And the creatures above the pool: The damselfly alights on a reed and rests with its transparent, netlike wings closed above its slim body. The stouter-bodied dragonfly rests with its wings outstretched and likes to fly in tandem. Both of these aerial beauties must lay their eggs in water, and their larvae are fully aquatic predators that breathe with gills like fish.
This flash flood (above) washed out a portion of the Maverick Road. Flash floods can be killers to the unwary. They can sweep down on you from storms you never saw or heard.
Cottonwood Creek’s wide bed suggests that it, too, knows rage. Low water levels favor algae growths whose colors mirror the cottonwoods’ refreshing verdure overhead.
Many of the same water insects inhabit yet another type of waterhole, the tinaja, a natural pothole that traps rain or runoff in solid rock. Dependent on rainfall, tinajas often dry up, yet they may be the only water source over a large area. If a tinaja is deep enough it may survive evaporation, but the water may shrink back so far below the lip of the bowl that animals cannot reach it. A cougar once drowned in a tinaja here because it could not climb out again. Tinajas may also turn into death traps for the plants and insects that inhabit them. In a well-balanced pool the algae create the oxygen and food that aquatic creatures need, but as the pool dries up there is less and less oxygen and the products of decay become concentrated. At last these become so poisonous that the reproductive engine cuts off and the pool is literally dead. But even a dead pool may be a source of life to outside animals.
Ernst Tinaja is a good site for watching desert wildlife. It lies in a rocky, canyon-like drainage near the Old Ore Road. Though the upper tank measures 6 by 9 meters (20 by 30 feet) animals may not be able to use it because when the water is 3 meters (10 feet) deep it lies more than one-half meter (2 feet) below the edge. But mule deer and javelina frequent the smaller pools, which likely hold algae and a roster of aquatic life.
Other important tinajas may be found on Mesa de Anguila. The mesa top has a maze of trails leading to and from tinajas that have served as a focus of life across countless centuries. You can find Indian shelters in the form of overhanging cliffs up and down a canyon, with a permanent tinaja right in the middle.
Like the so-called lower animals mankind has long been dependent on waterholes. Since the first prehistoric Indians came to Big Bend, people have lived beside springs and tinajas. And what a pleasant prospect you still find from the sooted rock shelters above Croton Springs as you look out across the grasslands and the tules at the spring, toward the crenelated wall of the Chisos. Rounded red boulders beside the spring contain age-old mortar holes, ground so deep you can stick your arm in up to your elbow.
Before the day of automobiles, all the peoples who traveled through Big Bend routed their trails from water to water. On the way to Oak Spring you can sit in the shade of a Comanche marker tree, a great oak bent in a bow with all its branches growing upright. Comanches marked a good campsite by tying a sapling down; with maturity it naturally assumed a horizontal or bowed position.
Who said the desert’s palette must be dull? Desert locusts show vivid greens and yellows.
As Big Bend opened to ranching, the need for more watering places grew. Ranchers drilled wells, put up windmills, and scraped out stock tanks. Some of these waterholes remain to this day. The wells at Dugout Wells and the Sam Nail Ranch are still maintained. Without regular care such improvements would soon disappear in the desert.
One of man’s inadvertent “improvements,” the tamarisk or salt cedar, has proved an unwelcome water guzzler. The tree is about the size of an ordinary apple tree, but it loses to the atmosphere about five times as much moisture as an apple tree does. In desert country where water is so scarce, tamarisks pose a serious problem. Brought to this country from the Mediterranean area for use as a windbreak, salt cedar escaped cultivation and spread like wildfire across the Southwest, invading river bottoms, drainage ways, and waterholes in unbelievable numbers.
The tamarisk spreads by runners and apparently reaches isolated springs when mammals and birds bring seeds in on their fur and feathers. Growing at the rate of nearly 2 meters (8 feet) in a summer, the deep-rooted tamarisk uses up a disproportionate amount of water and actually lowers the water table. It is useless to man, and wildlife does not browse it because it tastes so salty.
Big Bend National Park conducts a tamarisk eradication program as a water conservation measure centered about the springs. It is hot, dirty, time-consuming work because tamarisks are almost impossible to kill. No known creature can be used for control, and if you leave so much as a root hair, another tree will grow. You have to saw the tree off and paint the stump with a special approved chemical that does not harm other plants or wildlife and will not contaminate the spring. This effort to save the precious amounts of moisture stored in the Big Bend landscape requires constant vigilance and back-breaking effort.
Big Bend Ranching Days
Cattle ranching in the Big Bend began about 1870 when Milton Faver set himself up as ‘Don’ Milton not far from today’s Marfa. He eventually built five spreads, including the region’s first sheep ranch. As his headquarters he built a fort at Cibolo (Buffalo) Creek Ranch. The Army gave him a cannon for it and even garrisoned soldiers there under his command. During one difficult period, Indian raids wiped out all Faver’s livestock except 40 calves confined in the fort. With superb swapping he rebuilt his herds from the Indians new largesse. By 1880 more and more ranching was pushed west into the Big Bend by range shortages and overgrazing east of the Pecos River. Formal leasing and land purchases followed. The much sought-after lands had springs. Fencing soon put an end to the free range policy, but as late as 1890 cooperative roundups, branding, and drives were still required to sort out whose stock was whose. Stock was stolen by altering a legitimate brand. This came to an end with the introduction of barbed wire, which changed ranching considerably. Most of the grasslands have never recovered from overgrazing.
Branding.
A cattle drive.
Longhorns.
A roped yearling submits to inoculation.
Imported from the Mediterranean area for use as windbreaks, tamarisk spread quickly across the Southwest. This water guzzler—it loses five times more water to the atmosphere than an apple tree does—can actually lower the water table.
Big Bend has five seasons—winter, spring, summer, fall, and that extra blooming season that bursts out any time you have a good rain and other conditions are right. The more rain, the more spectacular the display, with flowers, buzzing insects, croaking toads, and nesting birds in a complete new cycle of regeneration. Imagine the gravel wastes of the Castolon floodplain awash with flowers—solid carpets of little white and yellow and purple blossoms on either side of the road. Running back from it are desert baileyas and grasses, with orange caltrop blowing like orange butterflies in the wind. Picture Cerro Castellan’s red flanks green, with pockets of ochre blossoms amid white heaps of volcanic ash. Imagine Mesa de Anguila’s talus slopes misted with grass, Santa Elena Overlook smelling garden sweet and so matted with little low-lying flowers that you cannot put your foot down without crushing dozens. You have never seen their like before and may not soon again, for this is the floral profusion that follows desert rains.
Most Big Bend rains come during the six warm months from May through October, but the expected rainfall may vary greatly with location and with elevation. Thus the super-dry desert between Mariscal Mountain and Castolon averages only 13 centimeters (5 inches) of rain in a year, while the Chisos mountaintops may get more than 50 centimeters (20 inches). Of course some years see more than the average, some years much less. Falling as it mostly does in torrents, very little rain penetrates the thirsty soil. The water just rolls down the slopes, rumbles through mountain canyons, gushes over a pour-off, roars along dry washes, and spreads out over lowland flats in fast-moving sheets heavy with mud. A flash flood can root up and carry off trees and other plants, animals in their burrows, automobiles and their occupants, rocks, and the very earth itself. Then almost as quickly as it came, it may go, leaving gouged and gullied desolation in its wake. Yet in a matter of days, these cracked and peeling mudflats may blossom like a garden.
The reason is that millions and billions of wildflower seeds lie dormant here, waiting for just the right combination of soil temperature and moisture to germinate and burst into bloom. Desert annuals do not store up water as the cactuses do. They do not put down deep taproots as the creosotebush does. Nor do they dress themselves in thorny, waxy, or woody shields as do the desert shrubs. Desert annuals look for all the world like their counterparts in more temperate country. They are just as colorful, just as lavish with leaves, and just as spendthrift with moisture. They live a brief, gaudy life in a hurry, completing the cycle from germination to seed production in a few, short, water-wasting weeks before the desert dries out once again. Then they pass months or even years in the seed stage, waiting for another rain and another burst of luxuriant life. This system works because the flowers produce so many seeds, and because the seeds themselves are marvelously drought resistant and programmed to sprout only at the right time and in the right place.
Each annual and perennial species has its own preferred blooming season and favored locale. The long-legged Big Bend bluebonnet may start flowering in December and keep on blooming until June. Sometimes this rangy relative of the Texas bluebonnet will bloom in such masses that the lowlands look like they have been painted blue. The daisy-shaped nicollet also likes gravelly soils, while the desert verbena does best in disturbed areas. This lavender-pink sweet william, a spring bloomer in the lowlands, appears later at higher elevations as springtime ascends the mountains. As a rule the spring bloom peaks in the lowlands in April, and species that prefer higher elevations flower a little later. Thus the bracted paintbrush begins to flaunt its red flags in June grasslands, and beautiful, deep blue tube-flowers may be seen from May to July on snapdragon vines in the Chisos woodlands. Usually the luxuriance of the spring bloom will depend on the amount of rain that fell during the preceding fall and winter, and the months of June and July are apt to show few flowers at lower, drier elevations. But with summer rains in August and September, many springtime flowers bloom again, sometimes more spectacularly. These rains also produce a bright first flowering from such summer and fall species as the low-lying, sweet-smelling limoncillo, and the broomweed that gold-plates Basin hillsides right through October and November.
Flowers
Orange caltrop
Desert baileya
Silverleaf
Thistle
Prickly poppy
Evening primrose
Dayflower
Cardinal flower
Many insects pass the dry months as the seeds do, lying dormant in eggs or cocoons. The same life-giving rains that waken the seeds quicken the insects. And as the flowers come into their own there is a mass emergence of flying, crawling, and creeping creatures. The timing of this double emergence is no accident. While the plant-eating insects feed, they also pollinate the flowers.
So beautifully coordinated are these adaptations that specialized flowers attract the very insects that do them the most good. Bees perceive color in the range of the spectrum from yellow through ultraviolet, and you will find them on the many yellow flowers of the pea family, blue larkspur, and lavender ruellias. Bees don’t distinguish red and orange, so they pass up the brilliant paintbrush which does attract hosts of butterflies. Flies, beetles, and other insects pollinate relatively unspecialized plants like the sunflowers. And night-flying moths respond to the whites and yellows that almost glow in the dark. In its caterpillar stage, the sphinx moth eats the leaves of the night-blooming evening primrose. When it matures the sphinx moth returns to the primrose and, hovering like a hummingbird, unrolls its retractable tongue and takes up nectar, thus paying its debt to the primrose by pollinating the flowers.
Insect-eating and seed-eating birds capitalize on each rain-induced harvest. The mourning dove, a common park resident, usually nests in the spring, but it may also nest again later in wet years. The scaled quail may produce as many as four broods in wet years, and you may see little brown chicks in mid-October. You may even happen on a young brown towhee high in the Chisos as late as November. Barn swallows and cliff swallows, both summer residents, nest as soon as they arrive in the spring, and breed again in wet years during August. The blackthroated sparrow may nest in both spring and summer if rains have produced a good crop of seeds, while the rufous crowned sparrow is actually busier nesting in wet summers than in dry springs. The black-chinned sparrow apparently waits for summer’s rainy season to nest.
Some mammal populations also rise and fall with the rains. Ord kangaroo rats may not breed at all during long periods of drought, but when a good rainy season produces an abundance of seed, most females soon become pregnant and produce two litters. Females of the first litter may even bear young of their own in the same breeding season.
Rock-nettle graces the limestone cliffs along the river, one of few plants to do so. You may also find it in the lower mountain canyons. Watch for its blossoms from November through May.
Ethereal canyon reflections on quiescent waters beckon you toward the timelessness many experience within these vault-like Rio Grande gorges.
As the Wild River Runs
At 3,000 meters (10,000 feet) the golden eagle glides on outspread wings, his head cocked down so he can watch for signs of life upon that motionless desert rolled out like a relief map below him. Largest of Big Bend’s airborne predators, the eagle needs an enormous hunting range, and riding the warm air currents high above the border, he can see it all: the flattopped and arched mountains, the sun-bleached lowland, and the silver Rio Grande disappearing and reappearing as it runs downstairs through steep canyons and open valleys. Tilting his two-meter (7-foot) wings, the eagle slipslides for a closer look into a canyon, spots the wake of a surface-swimming snake, folds his wings, and dives like a fighter jet. Before the snake even senses its peril, it is snatched aloft and hangs wriggling in the eagle’s talons as the great bird, feathered to the toes, lifts and flies up the canyon with mighty, measured wingbeats.
The waters dripping from the hapless snake’s body come from mountains far to the south and north. The Rio Grande begins in springs and snows high in Colorado’s Rockies, but backed into reservoirs and doled out to irrigate New Mexico and Texas farmlands, it may hardly even flow below El Paso. What gives the river a new lease on life is the Rio Conchos. This beautiful stream rises in the western Sierra Madres and flows northeastward across Mexico, cutting canyons of its own and joining the Rio Grande at Presidio, 160 river-kilometers (100 river-miles) above the park. Some geologists say it was the Rio Conchos, and not the Rio Grande, that cut those gorgeous canyons in the park. No one knows for sure. But once the river trapped itself, all it could do was dig deeper and deeper by processes that are still at work today.
A walk along a sandbar will show you that the river functions as a practical sorting machine. The water rolling by is so laden with sediment that you cannot even see rocks 13 centimeters (5 inches) below the surface. On the bar itself a layer of curling and flaking mud lies on top of the larger stones and gravel, which have fine sand deposited between them. The heaviest rocks settle out first, then the sand, and finally the finest particles. Water is a powerful lifting and pushing tool, but these water-borne abrasives do much of the river’s work, wearing out the rock, undercutting cliffs, deepening and widening the canyons. It goes on at normal stages of water where the river runs less than a meter (2-3 feet) deep, during floods when it crests at more than 6 meters (20 feet), and even during droughts when in many places the river is too shallow to float a boat. So in the slow course of geologic time the mountains are worn away, spread across the valleys, and carried out to sea.
The only streams that have a chance of leaving the desert alive are those whose water sources lie outside the desert. There are few such rivers in the world: the Nile, the Indus, the Tigris and Euphrates, the Colorado, and the Rio Grande. And what a wealth of water-loving life the wild river brings to the Big Bend desert. You can hang big catfish by the gills from your saddlehorn and have your horse walk off with fishtail dragging the ground. So the fishermen tell you.
Cotton and food crops grew during the first half of this century at Castolon (top) and Rio Grande Village. Both floodplain settlements are popular stops for park travelers today.
A third riparian settlement, Hot Springs, offered resort accommodations in the 1940s.
Life in this watery world is sustained by a food pyramid based on a super-abundant supply of tiny bottom organisms. A third-meter (1-foot) square of riffle bottom has been found to contain more than 100 organisms. Most are larvae of flying insects: stoneflies, mayflies, dragonflies, damselflies, water and terrestrial bugs, various kinds of flies, midges, and dobsonflies. These curious little creatures have evolved ingenious ways of living, breathing, and eating underwater. Some worm-like caddisfly nymphs build protective cases around themselves, gluing pebbles, bits of shells, and plants together with saliva. They have three pairs of legs up front sticking out of the case and a pair of hooks holding on to it behind, so they can drag their houses with them as they feed. Damselfly larvae breathe through three leaflike gills that project from the hind end of the abdomen, and when warm weather comes they crawl ashore, split their skins, and emerge as gossamer-winged adults. The gills on stonefly larvae extend from the head and thorax, while mayfly nymphs have seven pairs of gills standing out like feathers along the sides of the abdomen. When oxygen is in short supply, mayfly larvae vibrate their gills rapidly so as to quicken the flow of water along their bodies. Some aquatic larvae build nets to catch dinner; a caddisfly nymph may spin a kind of silken windsock that he hangs underwater with the narrow end downstream, using the pressure of the current to keep his prey trapped. Some aquatic larvae eat microscopic plants, some eat insects, and some eat each other. Large dragonfly nymphs may even catch and eat small fish. Larvae are consumed by fishes, frogs, and turtles.
A rafter hauls out on a sandbank inside Mariscal Canyon, the middle—and most sheer-walled—of Big Bend’s big three canyons. River runners thrill to Tight Squeeze, in Mariscal Canyon, where a rock slab as big as a car compresses the river into a tricky gap.
Probably the best way to get to know the river is to get out on it. An easy run is through Hot Springs Canyon, by 90-meter (300-foot) cliffs and over nice little rapids. You put in at the site of the old Hot Springs spa, and take out at Rio Grande Village, having to paddle only at riffles.
Suppose it’s early on a fine October morning and you’re floating along with the current, watching the sky, clouds, cliffs, and river cane reflecting blue, white, tan, and green on the glossy brown surface of the water. The river is too muddy for you to see what lives in it, but you can see the signs: a spreading circle where a fish has snatched an insect from the surface; mysterious little dimples that look like miniature whirlpools; the beaked head and long neck of a Texas softshell poked up like a periscope. This big turtle’s shell is really hard except along the edges, but it is smooth and doesn’t have the plates you see on other Rio Grande turtles. The Big Bend slider feeds primarily on plants, while the yellow mud turtle enjoys water insect larvae. And ready to oblige is a cloud of mayflies whirling in mad nuptial flight a meter or two (3-7 feet) above the water. They only live one day and exist as adults simply to mate, but they will sow the river with numberless eggs.
As you round a bend, a pair of great blue herons lifts from the shallows where they’ve been standing stilt-legged. Now with necks folded and long legs dangling they flap across to the farther shore. Ahead of you a blue-winged teal keeps lifting and settling further downstream. Ducks are seldom seen on the river in summer, but a dozen different species put down as migrants, and some even winter on the river. Now a slim pair of inca doves crosses overhead; you see the flash of rufous wings and white tail feathers. On a sandbar stands a spotted sandpiper, head low and tail high. He takes a step, stops, teeters up and down, and then flies.
The sandbar itself snugs in against the cliffside with greenery growing in three distinct tiers. River cane and mature salt cedar stand 4.5 meters (15 feet) tall against the flagstones. And stairstepped in front of these are seepwillows—not a willow at all, but a kind of sunflower that pioneers sandbars—and a younger, shorter stand of salt cedar. The canebrakes fairly crackle with wintering birds: black phoebes, cardinals, brown-headed cowbirds, and a migrating yellow warbler, perhaps. There is plenty for them to eat in that thicket. You yourself discover a nursery of orange true bugs beautifully crossed with olive green, all crowded together in every stage of development on two or three willow leaves. But the most intriguing thing about that sandbar is the record left by its visitors: a lizard’s five-toed track with the long unbroken mark made by its tail, and the great blue heron’s left-and-right footprints striding along almost in a straight line. You find the cat-like tracks of the ringtail, the dog-like tracks of the gray fox, and the flat-footed print of the hog-nosed skunk, pear-shaped as a bear’s. At the water’s edge honey bees are collecting moisture to water-cool their hive. One by one they sip and lift off, making a beeline for a cliff.
In the canyons where water flows from wall to wall, you find shore life restricted to those few plants and animals that can make a home on a cliff face. A spindly tamarisk has established a roothold in a thimble-sized deposit of soil just above waterline, and in cracks and crevices higher up, ocotillo and pricklypear are working down from the desert that tops the wall. Empty cliff swallow nests cluster on the undersides of overhangs. In spring you might see baby birds poking their heads from the colony’s doorways.
Along the border, people call the Rio Grande by its Mexican name, Rio Bravo del Norte. Nowhere does the river seem more wild, more powerful than inside Santa Elena, Mariscal, and Boquillas Canyons. To enter one of these mighty limestone vaults is to understand why mankind has always had to skirt canyon country, and why to this day, except for its historic fords, the river is all but impassable. If you go in by boat the only way out is through. The adventure calls for preparation, knowledge, hardiness, and considerable skill.
Cliff swallows colonize with as many as 50 nests in close order. How the adult birds pick out their own condominium from among such clusters remains a mystery.
But even a landlubber can stand in the canyon’s primeval presence. All you must do is make it up the ramps and steps that climb the cliff face at the mouth of Santa Elena, then follow the foot trail down again into the canyon. Looking up from the base of these 450-meter (1,500-foot) walls, you see a vulture and a raven soaring side by side along the canyon’s rim. To them you must seem small and as foolishly occupied as the ants drawn up in opposing lines across the sandy path. One step and you could crush the horde. One rock fallen from that height and you are gone. One wild storm upstream and you, the ants, and the sandbar are all washed away forever. Yet you are somehow drawn farther and deeper into the canyon, into this jungle of dark green tamarisk and emerald bermuda grass, through this labyrinth of water-polished boulders, to land’s end and water’s edge, to the very Beginning that laid these fossil oyster shells in this fierce rock.
Here in the canyon’s deep, vault-like isolation the sense of time, that ominous, inhuman distance of the Earth’s past, may come over you as the imagined shadow of the wings of a prehistoric reptile, the Pterosaur, perhaps, from 65 million years ago. This was the biggest flying animal ever known to have lived. Picture a 70-kilo (150-pound) flying reptile with a wing spread of up to 11 meters (36 feet), a foolishly long neck, and large head with a long, slender, toothless jaw. Add long legs, and short toes armed with sharp, hooked claws, and a body covered with fur-like material. And figure that each of those long, narrow, glider-type wings was a thin membrane supported by a single overgrown finger, and attached to the body, bat-style, right down to the knee. How could such a huge, ungainly thing ever lift off or fly?
A species does not survive unless it can compete for food and escape its predators, and Pterosaurs, both large and small, existed alongside aggressive, meat-eating dinosaurs for 140 million years. Unlike some smaller species found elsewhere, the Big Bend Pterosaur does not seem to have fished the ocean. At that time, Big Bend offered a river and floodplain environment far from the sea. No one knows how this giant Pterosaur made its living.
How the Canyons Were Formed
Some 200 million years ago this region lay under a sea whose sediments formed the structural, limestone bedrock patterns of the Big Bend. The basic landscape configurations of today’s park were set in motion 75 to 100 million years ago as the landscape emerged, folded, and faulted. Then erosion set in.
The ancestral river that carved Santa Elena, Mariscal, and Boquillas Canyons through bedrock was the Rio Conchos. (The present Rio Conchos contributes most of the water flowing through today’s Big Bend. It flows into the Rio Grande just upstream of the park.) When the ancestral river hit the limestone mountain uplifts, it had no alternative but to cut its way through. Steep-walled, narrow canyons resulted. Santa Elena Canyon is cut through the Mesa de Anguila. Mariscal Canyon severs its namesake mountains. Boquillas Canyon, the longest, cuts through the massive limestone Sierra del Carmen. You can see how steep these canyons are by taking a river trip (see [page 122]) or hiking park trails (see [page 119]) to the river or to canyon rims.
The region was once much higher in elevation than it is today, but erosion has taken its toll. Mountains and mesas are landscape formations whose rock erodes more slowly than surrounding materials do. Castle-like peaks and high, sharp-rimmed mesas stand as weathered monuments to earlier times when elevations were higher. Such stranded vestiges of geologic eras punctuate the stark Chihuahuan Desert landscape with eerie architecture. Astronauts have used Big Bend terrain to simulate moonscapes.
The sequence of geologic diagrams shows how the Big Bend canyons formed and what their future would be if slow processes of erosion continue.
① Faulting uplifts bedrock to form the mountain mass.
② Streams erode the mountains and begin to deposit sediments in the valley.
③ Streams continue depositing valley sediments eroded from the mountain mass.
④ Streams have now cut clear through the sharply eroded mountains and formed steep-walled canyons.
⑤ All but isolated mesa remnants of the mountains have eroded and weathered away. The riverbed rests in the deep layer of sediments.
⑥ In a future stage the bedrock mountain uplift might be entirely eroded away to become a deep layer of sediments.
When you think that the Earth is perhaps 4.5 billion years old, that complex organisms have existed for no more than about 700 million years, that the oldest rocks exposed in the park are 300 million years old, and that fossils of backboned animals in the park cover a time span of 70 million years, you can realize how fragmentary the fossil record really is. You get few glimpses of the relatively recent past, but these are astonishing.
For example, geologists know that back in the dim dark distances of Earth time, Big Bend lay repeatedly at the bottom of the sea. Convulsions within the Earth repeatedly raised these sea floors to the tops of mountains, and time after time these mountains wore away. One of the ancient ocean beds can be seen at Persimmon Gap where, in remnants of the park’s oldest mountains, fossil sponges, brachiopods, and other simple marine organisms lie exposed. For hundreds of millions of years the three-lobed trilobite was among the most prolific animals in the world, but it had long been extinct when the last great ocean, the so-called Cretaceous sea, washed across Big Bend. Most of Mexico lay submerged and a sort of mid-continent seaway cut North America in two about on the line of the Rocky Mountains. In its early stages this sea harbored ancestral clams, oysters, snails, corals, and a coiled shellfish called an ammonite. You can see these animals preserved in the limestone walls of Santa Elena Canyon. Giant clam shells a meter (3 feet) across and fossil fishes preserved in the round between Boquillas and Mariscal Mountain tell us what lived in later seas. Sea turtles, sharks, and a 9-meter (30-foot) marine lizard that swam in the open ocean have left their remains in the yellowish badlands near the park’s western entrance.
Late in this oceanic period the Rocky Mountains began to rise to the north of Big Bend, the Sierra Madre to the south. The park’s own Santiago, del Carmen, and Mariscal ranges, and the first upward thrust of the Chisos also occurred at this time. As the mountains rose and started to wear away, delta deposits began to build out farther and farther into the seaway, forming barrier bars and tidal shelves where turtles, snails, oysters, and sharks lived and died. Gradually the near-shore, subtidal environment changed to a tidal flat. This in turn changed to marsh, to beach, to brackish and freshwater lagoons, and finally to an estuary and river floodplain environment. Such was the Big Bend world to which the dinosaurs came. They had been ruling the Earth for eons, but they did not reach the park until the Cretaceous sea withdrew.