Tinajas Altas Mountains

The range is named for the Tinajas Altas ("High Tanks"), which are a series of perched waterholes on the range's eastern side approximately four miles north of the international boundary. The waterholes figured prominently in the history of the area as they were for years the only reliable source of water for many miles. The Quechan, Cocopah, and Hia C-eḍ O'odham are known to have used the waterholes regularly. It was an important camp for the Hia C-eḍ O'odham, whose elders have described hundreds of people living there seasonally as recently as 1885. Indigenous people of the area lived mostly by hunting bighorn sheep and gathering desert plants such as Mesquite and Palo Verde. Indigenous art remains visible on the walls of Tinajas Altas Canyon, alongside remnants of day to day life such as bedrock metates, potsherds, and rock circles. Early Europeans reported seeing piles of sheep horns near the tanks, likely a result of Hia C-eḍ O'odham hunting traditions which involved cremating the bones of hunted sheep and ceremonially disposing of them away from camps, but none of these piles remain today. The Tinajas were also a favorite ambush site for both Apache raiders and settler bandits. As the gold rush was tapering off in the early 1850s, Joaquin Murrieta was known to stop regularly at Tinajas Altas. Following the Gadsden Purchase of 1854 the range was absorbed by the United States, and the surveying commission for the new border watered at the tanks in 1855. Traffic on the Camino declined steeply following the completion of the Southern Pacific Railroad in 1877, although Tinajas Altas still saw prominent visits from Raphael Pumpelly, Carl Lumholtz, Kermit Roosevelt, and at least one party of Mexican Revolutionaries in the late 19th and early 20th centuries. Most visitors to Tinajas Altas over the past century, however, have been researchers or tourists drawn to the site's unique history and ecology. Since 1941 the site has been included in the Barry M. Goldwater Bombing Range and used for training of troops from Marine Corps Air Station Yuma. Despite this, no military activities occur in the immediate vicinity of Tinajas Altas, and the area remains open to the public. In recent years Prevention Through Deterrence policies have pushed immigrants further into remote areas of the range, and the Camino del Diablo, including the Tinajas Altas range, has once again become a perilous route for migrants on foot. ==Geology and geography==

Geologically, the Tinajas Altas Mountains are a southeastward extension of the block faulted Gila Mountains, and what are now the Tinajas Altas Mountains were actually considered part of the Gila Mountains until about the middle of the 20th century. The two ranges are separated by Cipriano Pass, also referred to as "Smugglers Pass," about two miles northwest of Raven Butte, which is a notable dark-colored volcanic feature on the eastern flank of the otherwise light-colored granitic range. The range lies in the Lower Colorado subdivision of the Sonoran Desert. This subdivision is sometimes referred to as the Colorado Desert and encompasses much of southeastern California, southwestern Arizona, northwestern Sonora, and northeastern Baja California. The subdivision is characterized by minimal precipitation, and the area around the Tinajas Altas Mountains averages only about three inches of rainfall per year. Mexican topographic maps and United States Geological Survey (USGS) maps of the region disagree on the name of an adjacent range lying to the southeast of the Tinajas Altas Mountains. In the United States this small range is referred to as the Sierra de la Lechuguilla, but in Mexico they are called the Sierra Tinajas Altas which would suggest that they are a longer extension of the Tinajas Altas Mountains into Mexico. The two ranges, however, share no surface connection so they are not the same. The Sierra de la Lechuguilla/Sierra Tinajas Altas range are instead on a parallel alignment to the southeast of the Tinajas Altas Mountains proper. The closest community to the Tinajas Altas Mountains is Fortuna Foothills in the east of the Yuma Valley adjacent to the Gila Mountains. ==Ecology==

The Tinajas Altas Mountains exhibit a variety of flora and fauna species. Among the notable flora present is the elephant tree, (Bursera microphylla), which species exhibits a contorted multi-furcate architecture. ==See also==