Otero Mesa is a 1.2 million acre (4,900 km²) area in northern Chihuahuan Desert region of southern New Mexico. Between 1954 and 1965 the U.S. Army expanded its McGregor Range facilities at Fort Bliss onto Otero Mesa by purchasing ranches. In 2005, the Bureau of Land Management approved the area for exploratory drilling for oil and gas, but that approval is currently being litigated by the state of New Mexico and environmental groups who want the mesa to be recognized as protected wilderness.