The Apache Mountains stretch from south central to southeastern Culberson County a mile northeast of Kent (their center point is 31°11' N, 104°21' W). The highest elevation within the Apaches is 5,650 feet above sea level. The mountains, presumably named for the Mescalero Apaches who roamed the area until the late nineteenth century, are one of three exposed portions of the largest fossil reef in the world (the others are the Guadalupe Mountains in northwestern Culberson County and the Glass Mountains in Brewster County). The reef was formed during Permian times, some 250 million years ago, when the area was submerged in the Delaware basin. Lime-secreting algae were the main reef-builders, with some sponges, bryozoans, and brachiopods; their remains and the lime they secreted formed the reef. The Apaches are steep and rocky with local deep and dense dissection. The shallow, stony soil surface supports oak, live oak, juniper, mesquite, piñon, and grasses. During the 1960s barite was mined from open pits in the Seven Heart Gap area of the Apaches, and some production of zinc was reported from the Buck Prospect.