Black Gap WMA

Phone: (432) 376-2216
55 miles south of Marathon, 18mi down FM 2627
See maps and directions for specific location

Contact: Travis Smith

Dates Open: Open year round, except closed for Special Permit hunts. Contact the WMA for specific information.


The Black Gap WMA borders Big Bend National Park on the northwestern boundary. The management area shares 25 miles of the Rio Grande with the Mexican State of Coahuila on the southern and eastern boundaries. The property contains approximately 103,000 acres where the Sierranias del Burro and Sierra del Carmen Mountain Ranges enter into Texas. The management area is also located in some of the lowest elevations of the Chihuahuan Desert found in the United States. The property serves as a facility where research and demonstration projects can be implemented to aid private land management of natural resources.

Dating back to the late 1800's, ranchers in the xeric southern portion of the Big Bend region historically raised sheep, goats, and some cattle. By the 1940's, much of the region had become overgrazed due to limited annual rainfall and the inability of the land to quickly recover. The Texas Game and Oyster Commission, the predecessor of the Texas Parks & Wildlife Department, purchased the original 54,000 acres from the Combs Cattle Company in 1948. Biological surveys after the purchase indicated that the vegetation had been overgrazed, there were insufficient surface waters, and the mule deer population was very low.

Between 1949 and 1951, 300 mule deer were trapped near Sanderson and released onto the management area to supplement the native deer population. The deer population had reached approximately 900 in 1955. The first public deer hunt was opened that year. The decision was made in 1963 to test the deer population to severe hunting pressure. Research on the seasonal movement of mule deer was conducted on the property between 1957 and 1963. An additional study took place in 1962-66 to observe the rate of utilization of artificial water sites by the deer. The information attained from these studies was instrumental to determining future mule deer management practices on private and public lands in the Trans-Pecos region.

Re-vegetation efforts were made in 1955 by making "push up's" with the aid of bulldozers. These pits were then seeded with johnson grass. This served to break the hard soil surfaces so other plants can emerge and to ensure that the soil contained a fresh seed bank for the future. These sites can be seen in the northwest portion of the property in the Shurley Flat. In 1967, selected sites were disked and seeded with sorghum and Lehmann's love grass. These sites were intended to cool the soil surface, allowing native plants to become established. One such site in Bighorn Valley has recovered so well that the native tobosa grass has pushed out the sorghum and the love grass, restoring the site to its natural state. Small food plots have occasionally been planted to provide diverse foods for migrating birds on the area.

Water is the key limiting factor to life in a desert. In the 1948 biological survey, the property contained insufficient surface water. Beginning in the late 1940's and 1950's, old dirt tanks were cleaned of silt and additional tanks built. During this period, the country was suffering from a severe decade long drought. In the southwestern states, artificial water catchments, called guzzlers, were being tested. There are three types that are used here. These are the slickrock, concrete, and "conventional" designs. The slickrock guzzler uses the lay of a natural smooth rock slope and a dam to slow runoff water. This water then is piped to a storage tank and a water trough. The concrete guzzler uses a concrete apron to collect water. The water is stored in a partially buried concrete cistern. This cistern has an open end opposite of the apron where wildlife can descend a slope to drink from it. The conventional design uses an upside down tin roof to collect water. The water is caught by a center gutter and is gravity fed to a storage tank and a trough. At least thirty-five guzzlers have been built in the last fifty years throughout the property. Between 1992 and 1999, five slickrock and seven conventional guzzlers have been donated and built by the Texas Bighorn Society.

In the late 1880's, the desert mountains in the region supported native populations of desert bighorn sheep (Ovis canadensis mexicana). The sheep were freely hunted for their meat and to reduce the competition between domestic sheep and the bighorns. Although there were no official counts of the bighorn at that time, it was estimated that there were approximately 1,500 bighorn sheep in West Texas. It was soon observed that the numbers were radically decreasing. The state outlawed the hunting and killing of the bighorn in 1903. By 1941 the estimated numbers were approximately 150 for the state. In 1957, re-introduction efforts were begun to trap bighorn sheep in other states and release them at a couple sites in Texas. The first efforts brought 16 sheep from southwestern Arizona to Black Gap WMA. A 427 acre pen was built to facilitate them. Meanwhile, the last native desert bighorn ewe was seen in the Sierra Diablo Mountains in 1958. By 1970, the Black Gap population had grown to 68. Twenty sheep were released in 1971. In that same year, the remaining sheep were affected by nutritional stress and disease. Predation became a factor in the decline of the local population. Six sheep were imported from Mexico to supplement the Black Gap herd in 1977. The last of these free roaming sheep were seen in 1985 on Black Gap. In 1994 and 1998, forty sheep were captured in Nevada and transplanted onto Black Gap. Fifty-eight sheep were transplanted from the Elephant Mountain WMA between 1995 and 2000. While the road to recovery was rough, today, the population is doing well. The bighorn sheep have expanded their range from the confines of the property; onto surrounding private properties in Texas & Mexico and into the Big Bend National Park.


Texas Parks & Wildlife's Wildlife Division adopted the following goals in 1989 for preparing management plans for WMA's.

Please Note
  • One campsite in the WMA headquarters campground and the composting toilet there are wheelchair accessible.
  • Visitors must bring their own water and pack out all trash.
  • The only restroom facility is located at the headquarters campsite.
  • Only "dead and down" wood may be collected for firewood.
  • All campfires must be in the provided fire rings. Camping is only allowed at designated sites for resource protection.
  • CAUTION: Watch for venomous snakes, insects, mountain lions, black bears and flash flooding.
  • First-aid supplies, sunscreen, basic car repair kit and food should be taken along for emergencies.
  • Access restricted to Maravillas and Horse Canyons, Rio Grande and the headquarters campsite from March 1 to August 31.