The Tularosa Basin is located primarily in Otero County, New Mexico. It covers about 6,500 sq mi (16,800 km2) (35% larger than Connecticut). It lies between the Sacramento Mountains to the east, and the San Andres and Oscura Mountains to the west. The basin stretches about 150 mi (240 km) north–south, and at its widest is about 60 mi (100 km) east-west. It is geologically considered part of the Rio Grande Rift zone, which widens there due to the slight clockwise rotation of the Colorado Plateautectonic plate.
Hydrologically, the Tularosa Basin is an endorheic basin, as no water flows out of it. The basin is closed to the north by Chupadera Mesa and to the south by the broad flat 4000-foot-elevation plain between the Franklin and Hueco Mountains, with the conventional boundary taken to be the New Mexico–Texas border. Surface water that does not evaporate or soak into the ground eventually accumulates at playas (intermittently dry lake beds), the largest of which is Lake Lucero, at 3888 feet elevation, at the southwest end of the White Sands dunes. The White Sands are a 710-km2 (275-mi2) field of white sand dunes composed of gypsum crystals. To the north of Lake Lucero are extensive alkali flats, which produce additional gypsum for wind deposition on the dunes.
The White Sands fossil footprints in the Tularosa Basin are estimated by the National Park Service to be 21 000 to 23 000 years old and include footprints possibly showing humans stalking a giant sloth.[1] The footprints are located at the shore of an ice age era lake. As of November 2021, 61 fossil footprints have been found at the site.[2]
Apache, Spanish, and U.S. 'Old West'
When the Spanish arrived in the Tularosa Basin, they found springs and small streams coming from the Sacramento Mountains that fed a relatively lush grassland on the eastern side of the basin. While the Spanish tried some sheep ranching and some mining, the area remained firmly under Apache control until the 1850s, when the United States established its military presence at Fort Stanton (in the Sacramento Mountains) (1855–1896), Torreon Fort (near Lincoln) (1850s), and Camp Comfort (1858–1859) at White Sands. Under US military protection, the first permanent settlement was established in 1862, when about 50 Hispanic farmers from the Rio Grande Valley moved to Tularosa. Efforts to control the Apache waned somewhat during the American Civil War and serious American settlement did not begin until the late 1870s, when settlers and cattle ranchers from Texas began moving into the basin. In 1969, the Gemsbok was introduced.
The nativegrasslands in the Tularosa Basin were able to support large herds in the wet years of the 1880s. When the Americans first started running cattle, in some places, the native perennial bunchgrasses grew 'as high as a horse’s shoulder' - 1.0–2.5 m (3.3–8.2 ft) depending on species. One cowboy estimated in 1889 that 85,000 head were mustered within the basin, but said that was "far too heavy a burden for the range" - or beyond its carrying capacity.[3] Severe drought followed for years, and the grassland pastures never recovered from the overgrazing, which continued in many instances for 75 years or more and caused top-soil erosion and desertification. Even within the White Sands Missile Range, where cattle grazing was eliminated in 1945, the effects from the 1890–1945 period of overgrazing can still be seen nearly everywhere. Many areas that were historically known to be rich perennial grasslands are now xeric desert shrublands, with creosote bush—(Larrea tridentata) predominating.
Groundwater salinization
Since surface water was unable to sustain the cattle herds, ranchers turned to groundwater, and the easily reachable aquifer of 'sweet water' was pumped out and depleted from under the basin, leaving only brackish water. Applying the groundwater to the surface resulted in additional salts being dissolved and transported back down by groundwater recharge into the aquifer, increasing its salinity. By 2000, it became clear that salts in the aquifer needed to be significantly reduced if existing levels of water use were to continue. Therefore, in 2004, the Tularosa Basin National Desalination Research Facility was established in the basin at Alamogordo, as a joint project of the Federal Bureau of Reclamation and Sandia National Laboratories. It is a national center for researching procedures to reduce brackish water creation and to develop new technologies for desalination as it is increasingly found in present-day inland basin aquifers with agricultural irrigation and potable water withdrawal demands.
Ecology
The Tularosa Basin is in the Chihuahuan Desertecoregion, with the former Great Plains grassland habitat ecotones. Because of the closed nature of the basin, a number of unique ecological niches have developed. A significant number of endemic species are only found in the Tularosa Basin. These include the White Sands pupfish (Cyprinodon tularosa) and the Oscura Mountains chipmunk.
