Hueco Tanks State Park and Historic Site, thirty miles east of El Paso, features three massive granite hills that rise to about 450 feet above the desert floor and are noted for their prehistoric Indian rock art. Hueco, Spanish for "hollow," refers to the hollows in the rocks that collect rainwater, which has long been one of the chief attractions in this arid land; around 1860 the tanks were capable of holding a year's supply of water. Until about 1910 they furnished virtually the only water between the Pecos River and El Paso. The hills may have been formed thirty-four million years ago by a molten mass of rock ejected from the earth's interior into a layer of sedimentary rock. As the softer stone weathered away, the irregular masses of syenite porphyry (a low-grade granite) were eroded into the present shape and dented with countless huecos. The moisture and soil conditions at Hueco Tanks have supported a remnant oak-juniper woodland that has disappeared from most of the surrounding area. In addition to the Arizona oak and one-seed juniper, many Chihuahuan Desert and grassland plants are found. Animal life in the area ranges from many types of rodents to kit and gray fox, with golden eagles, mule deer, and mountain lions occasionally seen. Several species of desert shrimp can also be found in the huecos following a rain.
Folsom projectile points found at Hueco Tanks show that human beings have been in the area for at least 10,000 years, following the bison herds. After the big-game animals disappeared, other people came to Hueco Tanks, hunting and gathering whatever food they could find and living in partially underground pit houses. This was the Desert Archaic Culture. About A.D. 1000, agriculture was introduced into the area, and the Jornada Branch of the Mogollon Culture developed; they supplemented their hunting and gathering with farming, made and used pottery vessels, and began building aboveground adobe houses. Excavations by archeologist George Kegley in 1972–73 revealed that a pit-house village probably occupied for a hundred years (A.D. 1100–1200) was located just east of a natural opening into the protected bowl formed by the three outcrops. The village was composed of a number of semisubterranean jacal or wattle-and-daub single-room structures clustered in a thirty by forty meter area. The typical house (six were excavated) was square to rectangular, was oriented true north-south, had two postholes equidistant from the walls along the east-west midline, and had an bowl-shaped adobe fire pit with a collar or raised coping and plastered floor and walls. The living space averaged twelve square meters (130.5 square feet). A step or "altar" was located midway against the south wall on one house, and entry through the roof was postulated. By the beginning of the historic period, Hueco Tanks was being used by the Mescalero and Lipan Apaches and probably the Jumano Indians. Comanche and Kiowa raiders also camped there, as did the Tigua Indians of Ysleta. Each of the three cultures left vivid pictography at Hueco Tanks. An estimated 5,000 pictographs and a few petroglyphs are scattered in more than fifty sites throughout the park. Numerous experimental projects have been performed to halt deterioration and preserve the delicate paintings. Modern graffiti continues to threaten the rock art found adjacent to visitor facilities.
The early Spanish and Mexicans apparently rarely visited Hueco Tanks. Although there are tales of battles taking place, there is little documentation. One such battle may have occurred about 1839, when Mexican troops and their Tigua allies trapped a band of Kiowa raiders in a cave. According to Kiowa tales, most of the Indians escaped after a few days. Not until 1848–49 did Hueco Tanks begin to appear in the records with any frequency. After the Mexican War the discovery of gold in California lured adventurers westward by the hundreds. Several official expeditions were sent to open a road between Austin-San Antonio and El Paso. One, led by John S. (Rip) Ford and Col. Robert S. Neighbors, went by way of Hueco Tanks and established what became known as the Upper Road, which roughly parallels the present Texas-New Mexico border across far West Texas. In 1852 United States Boundary Commissioner John R. Bartlett, while surveying the boundary between the United States and Mexico, visited Hueco Tanks and recorded several of the pictographs in his journals. The Butterfield Overland Mail established a stagecoach station at Hueco Tanks in 1858, only to abandon it the following year in favor of a better watered and protected route farther south. In 1898, with the Apaches on the reservations, Silverio Escontrías acquired Hueco Tanks for a ranch. The Escontrías family operated Hueco Tanks until 1956, charging a small fee for visitors who came to enjoy the scenic area. After the tanks had passed through the hands of a few other ranchers, land developers moved in with plans for housing developments, lakes, frontier-town movie sets, golf courses, resorts, and restaurants. Fortunately, by the mid-1960s El Paso County acquired Hueco Tanks and began operating it as a county park. On June 12, 1969, the county gave Hueco Tanks by special deed to the Texas Parks and Wildlife Department. The department purchased an additional 121 acres from Barney Wieland, who had sold Hueco Tanks to the county, and in May 1970 Hueco Tanks State Historical Park was opened to the public. In 1998 the park was renamed Hueco Tanks State Historic Site. The site has a 1936 Texas Centennial marker and was included on the National Register of Historic Places in 1971. The 860-acre park, known in the 2010s as Hueco Tanks State Park and Historic Site, offers a variety of activities, including camping, picnicking, hiking, rock climbing, bird watching, and exploring.