National Parks › Desert Southwest › Big Bend

Big Bend National Park

Texas · Established June 12, 1944

Where the Rio Grande bends, a desert cradles a sky island of oak and pine

Area: 801,163 acres
Established: June 12, 1944
Recreation visits: 568,104 / yr
State: Texas
Highest point: Emory Peak, 7,832 ft (2,387 m)
Lowest point: About 1,800 ft (550 m), along the Rio Grande

Big Bend Weather Forecast

Loading the National Weather Service forecast for Big Bend…

Seven-day outlook at the park's reference point (29.298, -103.230). Elevation changes everything in the mountains — expect colder, windier and wetter conditions on high ground.

Map of Big Bend National Park

The Park

Where the Rio Grande makes its great southward bend along the Texas-Mexico border, Big Bend National Park spans an astonishing range of worlds: sheer limestone canyons, sun-baked Chihuahuan Desert, grasslands studded with sotol and yucca, and the cool, forested Chisos Mountains rising to 7,832 feet. The Chisos are entirely contained within the park, a true sky island stranded above the desert.

Established on June 12, 1944, Big Bend protects about 801,163 acres (3,242 sq km) and administers roughly 118 miles of the Rio Grande. It is remote, with around half a million visits a year, and it rewards those who come with some of the darkest night skies in the country, more bird species than almost any other national park and a geologic record that includes dinosaurs, volcanoes and ancient seas.

Geography

The park's outline follows the Rio Grande for its entire southern and eastern edge. At the western end, the river slices through Mesa de Anguila in Santa Elena Canyon; midway it cuts Mariscal Canyon through Mariscal Mountain at the southernmost point of the bend; and in the east it carves Boquillas Canyon through the Sierra del Carmen uplift. Elevations fall to about 1,800 feet along the river.

Between the river and the mountains stretches the Chihuahuan Desert, a land of creosote bush, lechuguilla and ocotillo broken by volcanic buttes, dry washes, badlands and scattered springs such as the oases at Dugout Wells and Sam Nail Ranch.

In the center rise the Chisos Mountains, an eroded volcanic range crowned by Emory Peak, Lost Mine Peak, Toll Mountain and Casa Grande. Their high basin, drained through a narrow notch called the Window, holds woodlands of pinyon, juniper and oak that are about ten degrees cooler than the desert below.

Landmarks

Emory PeakPeak · 7,832 ftThe high point of the Chisos Mountains and the park, reached by a steep trail with a final rock scramble.
Casa Grande PeakPeak · 7,325 ftA massive volcanic block that towers over the Chisos Basin.
Lost Mine PeakPeak · 7,535 ftA popular summit ridge with sweeping views of Pine Canyon and the Sierra del Carmen.
The WindowCanyonA narrow pour-off where the Chisos Basin drains, famous for framing desert sunsets.
Santa Elena CanyonCanyonA spectacular gorge where the Rio Grande emerges from sheer limestone walls of Mesa de Anguila.
Mariscal MountainPeakA remote limestone uplift at the southern tip of the bend, cut by Mariscal Canyon.
Boquillas CanyonCanyonThe longest of the park's river canyons, carved through the Sierra del Carmen.
Hot SpringsRiverA historic bathhouse site where warm spring water seeps up beside the Rio Grande.
Rio Grande VillageRiverA shady riverside oasis of cottonwoods, a prime birding area near Boquillas.
Cerro CastellanPeakA layered volcanic butte of colorful lavas and ash rising above Castolon.
Tuff CanyonCanyonA small canyon cut into soft, pale volcanic ash along the scenic drive.
Mule EarsPeakTwin volcanic spires that resemble a pair of upright mule ears.
Burro MesaPlateauA mesa of volcanic rock whose pour-off drops into a hidden box canyon.
Grapevine Hills Balanced RockAreaA huge boulder wedged atop granite-like igneous rock in the Grapevine Hills.
Fossil Discovery ExhibitAreaAn exhibit showcasing Big Bend's dinosaurs, giant crocodiles and early mammals.
Persimmon GapValleyThe northern gateway, where some of the park's oldest Paleozoic rocks are exposed.

Geology

Big Bend has been called a geologist's paradise because so much of Earth's history lies open to view. Near Persimmon Gap, rocks around 500 million years old record a long-vanished ocean that was later crumpled when continents collided and raised the ancient Ouachita Mountains.

During the Cretaceous Period, warm shallow seas returned and deposited thick limestones, including the Glen Rose, Del Carmen and Santa Elena limestones and the Boquillas Formation. These massive, resistant layers now form the walls of Santa Elena, Mariscal and Boquillas canyons and the high face of the Sierra del Carmen. As the sea withdrew near the end of the Cretaceous, rivers and floodplains laid down the Javelina and Black Peaks formations, where paleontologists have found the long-necked sauropod Alamosaurus, the giant pterosaur Quetzalcoatlus, the enormous crocodile relative Deinosuchus and the horned dinosaur Bravoceratops, known only from Big Bend.

The same mountain-building that raised the Rockies folded and uplifted these layers. Then the region became a cauldron. Volcanic eruptions built the Chisos Mountains between roughly 44 and 35 million years ago, and later episodes produced the Pine Canyon caldera, the lavas and ash of the Chisos Group, and the Burro Mesa Formation. Around 30 million years ago, the crust began to stretch, breaking into fault blocks that dropped the central basin and lifted the flanking mesas.

The final chapter belongs to the Rio Grande. The river arrived in the Big Bend region roughly two million years ago and has been cutting down ever since, holding its course as it sawed straight through rising limestone blocks to create the park's great canyons, while wind and flash floods sculpt the desert around it.

Deep time

About 500 million years agoDeep-ocean sediments are deposited; their remnants are exposed today near Persimmon Gap.
Late PaleozoicColliding continents fold these rocks into the Ouachita Mountains, now eroded away.
CretaceousShallow seas deposit thick limestones such as the Santa Elena Limestone and the Boquillas Formation.
72 to 66 million years agoRivers deposit the Javelina and Black Peaks formations, burying dinosaurs, pterosaurs and giant crocodilians.
About 44 to 35 million years agoVolcanic activity builds the Chisos Mountains.
Beginning about 30 million years agoCrustal stretching triggers further eruptions and vertical faulting that shape the park's basins and ranges.
About 2 million years agoThe Rio Grande enters the Big Bend region and begins carving Santa Elena, Mariscal and Boquillas canyons.

The rocks

Glen Rose LimestoneEarly Cretaceous
Marine limestone recording the advance of shallow seas across the region.
Del Carmen LimestoneEarly Cretaceous
A thick, cliff-forming limestone prominent in the Sierra del Carmen.
Santa Elena LimestoneCretaceous
Massive gray limestone that forms the towering walls of Santa Elena Canyon.
Boquillas FormationLate Cretaceous
Flaggy, fossil-rich marine limestone and shale laid down in a deeper sea.
Javelina FormationLate Cretaceous, 72 to 67 million years
River and floodplain deposits yielding Alamosaurus and Quetzalcoatlus.
Black Peaks FormationLatest Cretaceous, about 67 to 66 million years
Strata spanning the end of the age of dinosaurs, with fossil plants, gar and dinosaur bones.
Chisos GroupPaleogene
Volcanic lavas, ash and sediments that make up much of the park's colorful western landscape.
Burro Mesa FormationPaleogene
Volcanic rhyolite and tuff capping Burro Mesa and nearby uplands.

Trees, Plants & Ecosystems

1,326vascular plant species recorded

Rio Grande riparian corridorAbout 1,800 to 2,200 ft
Cottonwoods, willows, mesquite and cane line the river, supporting beaver, turtles, fish and nesting hawks.
Chihuahuan Desert scrubDesert lowlands and bajadas
Creosote bush, lechuguilla, ocotillo and candelilla dominate the hottest, driest ground, the park's most extensive habitat.
Desert grasslandFoothills and upland flats
Grasses mingle with sotol, beargrass and yuccas on igneous and limestone soils.
Chisos Mountains woodlandAbout 5,000 to 7,832 ft
Mexican pinyon, alligator and drooping junipers, and several oak species form a cool sky island home to black bears and Colima warblers.
Desert springs and oasesScattered across the desert
Isolated seeps and springs support stands of cottonwoods, dense thickets and outsized numbers of birds and mammals.

Trees

Mexican pinyonPinus cembroidesA small nut pine characteristic of the Chisos woodlands.
Arizona pinePinus arizonicaA tall, ponderosa-like pine surviving in the moist high canyons of the Chisos.
Alligator juniperJuniperus deppeanaNamed for its checkered, reptile-like bark, common in the Chisos Basin.
Drooping juniperJuniperus flaccidaA graceful juniper with weeping foliage whose U.S. range is essentially limited to Big Bend.
Emory oakQuercus emoryiAn evergreen oak of the mountain woodland with sweet acorns favored by wildlife.
Graves oakQuercus gravesiiThe Chisos red oak, adding color to high canyons in autumn.
Texas madroneArbutus xalapensisStriking peeling red bark and berries relished by black bears.
Bigtooth mapleAcer grandidentatumA relict of cooler times hiding in shady canyons like Boot Canyon.
Arizona cypressCupressus arizonicaA rare conifer found in sheltered, moist high-elevation canyons.
Douglas-firPseudotsuga menziesiiA northern conifer clinging to a few cool, high spots in the Chisos.
Honey mesquiteProsopis glandulosaA thorny desert tree whose deep roots tap groundwater along washes and the river.
Desert willowChilopsis linearisNot a true willow, it bears orchid-like pink flowers along dry washes.

Wildflowers, shrubs & other plants

Havard agaveAgave havardianaA big century plant that blooms once on a towering stalk and then dies.
LechuguillaAgave lechuguillaThe indicator plant of the Chihuahuan Desert, with dagger-tipped leaves that pierce boots.
Giant dagger yuccaYucca faxonianaA tree-like yucca whose huge flower clusters light up Dagger Flat in spring.
Beaked yuccaYucca rostrataA blue-leaved yucca of limestone slopes.
OcotilloFouquieria splendensTall, whip-like stems that leaf out after rain and flare with red flowers.
CandelillaEuphorbia antisyphiliticaA waxy-stemmed plant once harvested for candle and polish wax.
Creosote bushLarrea tridentataThe desert's dominant shrub, releasing its famous smell of rain after storms.
Smooth sotolDasylirion leiophyllumA spiky rosette with a tall flowering stalk, common in desert grasslands.
Chisos bluebonnetLupinus havardiiA tall, deep blue lupine that blooms in late winter and spring.
Big Bend barometerbushLeucophyllum minusA silvery cenizo that bursts into purple bloom after summer rains.
TarbushFlourensia cernuaA resinous shrub that shares desert flats with creosote bush.
BeargrassNolina erumpensTough, grass-like clumps with plumes of tiny cream flowers.
Horse cripplerEchinocactus texensisA low, flat barrel cactus with fierce spines hidden in the grass.
Chisos Mountain hedgehog cactusEchinocereus chisoensisA rare, federally threatened cactus found nowhere else but the Big Bend region.

Wildlife

80mammals
409birds
59reptiles
11amphibians
41fish

Mammals

American black bearUrsus americanusReturned naturally from Mexico in the 1980s and now lives in the Chisos Mountains.
Carmen Mountains white-tailed deerOdocoileus virginianusA small subspecies of white-tailed deer found in the high Chisos.
Mule deerOdocoileus hemionusThe large-eared deer of the desert lowlands.
Collared peccaryPecari tajacuJavelinas travel in herds and frequent springs and dense thickets.
Mountain lionPuma concolorPresent throughout the park, from river to mountains.
CoyoteCanis latransCommon in the desert, most active at dawn and dusk.
Kit foxVulpes macrotisA tiny nocturnal fox of open desert flats.
Gray foxUrocyon cinereoargenteusAn agile fox of rocky slopes and woodlands.
RingtailBassariscus astutusA nocturnal climber of rocky canyons and cliffs.
Mexican long-nosed batLeptonycteris nivalisAn endangered nectar-feeding bat that pollinates agaves in summer.
Brazilian free-tailed batTadarida brasiliensisOne of more than a dozen bat species hunting over the desert at night.
Merriam's kangaroo ratDipodomys merriamiA nocturnal seed-eater that never needs to drink.
Texas antelope squirrelAmmospermophilus interpresA small striped squirrel of rocky desert slopes.
American beaverCastor canadensisLives in bank dens along the Rio Grande.

Birds

Colima warblerVermivora crissalisNests in the United States only in the Chisos Mountains, a pilgrimage bird for birders.
Mexican jayAphelocoma ultramarinaNoisy family flocks patrol the Chisos woodlands.
Greater roadrunnerGeococcyx californianusA ground-running cuckoo that hunts lizards and snakes.
Scaled quailCallipepla squamataA cotton-topped quail of desert grasslands.
Common black hawkButeogallus anthracinusNests in riparian cottonwoods near Rio Grande Village.
Gray hawkButeo nitidusA subtropical hawk that nests along the river corridor.
Golden-fronted woodpeckerMelanerpes aurifronsA common sight in the cottonwood groves.
Vermilion flycatcherPyrocephalus rubinusMales glow scarlet around springs and riverside campgrounds.
Black-capped vireoVireo atricapillaA small vireo of shrubby mid-elevation slopes.
PyrrhuloxiaCardinalis sinuatusA gray desert cardinal with a red crest and parrot-like bill.
Cactus wrenCampylorhynchus brunneicapillusBuilds bulky nests in cholla and lechuguilla.
Lucifer hummingbirdCalothorax luciferA desert hummingbird with a curved bill that feeds on agave blooms.
Varied buntingPasserina versicolorA jewel-colored bunting of brushy desert canyons.
Peregrine falconFalco peregrinusNests on the high walls of the river canyons.

Reptiles & amphibians

Western diamond-backed rattlesnakeCrotalus atroxThe largest rattlesnake in the park, common in the desert lowlands.
Mottled rock rattlesnakeCrotalus lepidusA beautifully patterned small rattlesnake of rocky canyons.
Trans-Pecos copperheadAgkistrodon contortrixA handsome copperhead found near springs and moist canyons.
Trans-Pecos ratsnakeBogertophis subocularisA large-eyed, nocturnal ratsnake of the Chihuahuan Desert.
Big Bend canyon lizardSceloporus merriamiA rock-dwelling lizard that matches the color of the stone it lives on.
Greater earless lizardCophosaurus texanusFlashes a banded tail as it dashes across open ground.
Big Bend sliderTrachemys gaigeaeA turtle of the Rio Grande basks on logs and banks.
Couch's spadefootScaphiopus couchiiBreeds explosively in rain pools after summer storms.

Fish

Big Bend gambusiaGambusia gaigeiAn endangered fish found in the wild only in springs near Rio Grande Village.
Rio Grande silvery minnowHybognathus amarusAn endangered minnow reintroduced to the Rio Grande in the Big Bend reach.
Blue suckerCycleptus elongatusA streamlined native sucker of swift river channels.
Blue catfishIctalurus furcatusA large catfish of the Rio Grande's deeper pools.
Longnose garLepisosteus osseusAn ancient-looking predator of slow river stretches.

Species totals are the park's certified NPSpecies checklist (occurrence: present).

Climate & When to Visit

Big Bend sits in the Chihuahuan Desert, where sunshine is abundant in every season and rain is scarce. The park's enormous elevation range, from about 1,800 feet on the river to more than 7,800 feet in the Chisos, creates several climates at once: the Chisos are typically 10 to 15 degrees F cooler than the desert floor and noticeably wetter.

Spring is warm and pleasant and is the busiest season. Heat builds quickly from May, and through August the lowlands routinely exceed 100 F by late morning. Summer also brings the monsoon, when afternoon thunderstorms can flood washes and roads. Autumn and winter are mild and sunny, with occasional freezes, especially at night and in the mountains, while snow is uncommon.

Spring
Warm, dry and windy, with desert wildflowers and blooming cacti; March is often the park's busiest month.
Summer
Extremely hot at low elevations, often above 100 F; the Chisos Basin offers relief, and monsoon storms bring green-up and flash floods.
Autumn
Temperatures ease, the desert is often green after summer rain, and migrating birds pass through.
Winter
Mild and sunny by day, with cold nights and occasional freezing temperatures; rare snow may dust the Chisos.

Weather hazards

Extreme heat: Desert and river temperatures can exceed 100 F from May through August; hike early, carry a gallon of water per person per day and avoid midday exertion.
Flash floods: Summer storms can send water roaring down washes and across roads; never cross flooded low-water crossings.
Remoteness: Services, cell coverage and water are scarce, so carry extra fuel, water and a spare tire on backroads.
River hazards: The Rio Grande has strong currents, submerged obstacles and variable water quality; swimming is not recommended.
Lightning and wind: Exposed peaks and ridges are dangerous during summer thunderstorms, and spring winds can be fierce.

Big Bend Questions

When is the best time to visit Big Bend National Park?

October through April offers the most comfortable temperatures across the desert and river areas. March and spring break bring peak crowds and wildflowers, while summer is best reserved for early mornings or the cooler Chisos Mountains.

How hot does Big Bend get?

From May through August, desert and river temperatures often climb above 100 F by late morning. The Chisos Mountains are usually 10 to 15 degrees cooler, which makes the Chisos Basin the best summer refuge.

What makes Big Bend's geology special?

The park exposes rocks spanning hundreds of millions of years, from ancient ocean sediments and Cretaceous limestones to volcanic mountains and dinosaur-bearing river deposits. The Rio Grande has sliced through uplifted limestone blocks to create Santa Elena, Mariscal and Boquillas canyons.

Why is Big Bend famous for birdwatching?

Its mix of river, desert and mountain habitats, and its position on the edge of Mexico, attract more than 400 recorded bird species. The Colima warbler, which nests in the U.S. only in the Chisos Mountains, is a star attraction from spring into summer.

Are there bears in Big Bend?

Yes. Black bears live mainly in the Chisos Mountains, where they feed on acorns, madrone berries and juniper fruit. Store food properly and keep your distance if you see one.

Can you see stars at Big Bend?

Big Bend has some of the darkest skies in the lower 48 states and is recognized as an International Dark Sky Park. Clear, dry winter and spring nights are especially good for stargazing.

More parks in the Desert Southwest

← Badlands National Park Biscayne National Park →

Sources: www.nps.gov · www.nps.gov · www.nps.gov · www.nps.gov · irmaservices.nps.gov · en.wikipedia.org · en.wikipedia.org · Official NPS site