Castner Range National Monument is a national monument in El Paso County, Texas, that covers 6,672 acres (27 km2) of the Franklin Mountains. It was established by President Joe Biden on March 21, 2023. The monument, a former weapons testing range, is part of Fort Bliss and is managed by the U.S. Army as the only land conservation national monument within the Department of Defense. The monument includes the eastern slopes of North Franklin Mountain, the highest peak in the area. It is adjacent to Franklin Mountains State Park and Northeast El Paso and near the Organ Mountains–Desert Peaks National Monument in New Mexico. As remediation is ongoing, the site is closed to the public.

Fort Bliss is a United States Army post in New Mexico and Texas, with its headquarters in El Paso, Texas. Named in honor of LTC William Bliss (1815–1853), a mathematics professor who was the son-in-law of President Zachary Taylor, Ft. Bliss has an area of about 1,700 square miles (4,400 km2); it is the largest installation in FORSCOM and second-largest in the Army overall. The portion of the post located in El Paso County, Texas, is a census-designated place with a population of 8,591 as of the time of the 2010 census. Fort Bliss provides the largest contiguous tract of restricted airspace in the Continental United States, used for missile and artillery training and testing, and at 992,000 acres boasts the largest maneuver area. The garrison's land area is accounted at 1.12 million acres, ranging to the boundaries of the Lincoln National Forest and White Sands Missile Range in New Mexico. Fort Bliss also includes the Castner Range National Monument.