Big Bend National Park, established in 1944, encompasses the largest protected area of Chihuahuan Desert in the United States. The park protects 324,219 hectares (801,163 acres) of land located along the Rio Grande River on the border with Mexico in Texas. The park has desert and semi-desert grasslands, desert scrub and woodlands, montane chaparral, and montane woodlands. The park's Chisos Mountains are "sky islands" surrounded by desert. The montane habitats found here support boreal species such as quaking aspen and ponderosa pine, commonly found in northern latitudes.
A significant part of the park's tremendous biodiversity is represented by isolated populations of plants and animals found in the Chisos Mountains and in many of the desert springs distributed across the park. There are 1,717 plant species from 121 familes, 31 species of fish, 69 species of reptiles and amphibians, 75 species of mammals, and 413 species of birds in the park. The Chihuahuan Desert has more species of cacti than any other desert and than the entire state of Arizona.
Climate change is a great concern here, as there are no higher habitats to which forest species can escape as temperatures increase. Also, many plant and animal communities are relict, unique, geographically isolated, or exist on the margin of their range. Park elevation range is 548–2,387 meters (1,780–7,831 feet) and average annual precipitation ranges from 25 centimeters (10 inches) in the desert to 46 centimeters (18 inches) in the Chisos Mountains. We monitor air quality, climate, groundwater, invasive exotic plants, landbirds, river channel characteristics, springs, seeps, and tinajas, and terrestrial vegetation and soils at this park.
Reports & Web Articles
Read more about our work at this park in the resource briefs (short summaries), monitoring reports (detailed results), condition assessment (natural resource conditions), and web articles below. Inventories (baseline reports and lists of natural resources) and protocols (monitoring procedures) can be found on our reports & publications pages.