Oscura Mountains, originally known to the Spanish as the Sierra Oscura, are a ridge of mountains, trending north and south, east of the Jornada del Muerto and west of the Tularosa Valley. The word oscura means "dark" and refers to the dark color of the mountains due to the Pinyon-juniper vegetation at their higher elevations.[1] The Oscuras are located in Socorro County and Lincoln County, New Mexico.[2] Their southern end is at 33°30′30″N 106°18′45″W / 33.50833°N 106.31250°W and their northern end is at 33°49′15″N 106°22′20″W / 33.82083°N 106.37222°W near North Oscura Peak.[2] Their highest elevation is Oscura Peak at 8,625 feet (2,629 meters).[3]
The Oscura Mountains extend southward about 30 miles (48 km) from U.S. Route 380 and are 6 miles (9.7 km) to 10 miles (16 km) wide. To the west, dropping off sharply from the crest of the Oscuras, the austere desert of the Jornada del Muerto (Spanish: Dead Man's Journey) has an average elevation of about 5,000 ft (1,500 m). Southwest and separated from the Oscuras by Oscura Gap are the lower-lying Little Burro Mountains. The San Andres Mountains lie beyond the Little Burro Mountains to the south and are separated from them by Mockingbird Gap. The Oscura range is bounded on the north by Wash Hale Canyon. The Oscuras slope off more gently to the east and are bounded on the northeast by the Chupadera Mesa. The Tularosa Basin to the east also has an average elevation of about 5,000 ft (1,500 m)[2][4]
The Oscura Mountains are located within the White Sands Missile Range and public access is restricted. The Trinity site, the location of the first test of an atomic bomb in 1945, is 11 km (6.8 miles) northwest of Oscura Peak.[5] North Oscura Peak is the location of an Air Force Research Laboratory (AFRL) site. It rises to an elevation of 7,976 feet (2,431 meters).[6]