Black Mesa (also called Big Mountain) is an upland mountainous mesa of Arizona, north-trending in Navajo County, west and southeast-trending in Apache County. In Navajo it is called Dziłíjiin ('Black Mountain') and during Mexican rule of Arizona it was called Mesa de las Vacas (Spanish for 'mesa of the cows').[1] It derives its dark appearance from its pinyon-juniper and mixed conifer woodlands.[2]