Pah-Ute County is a former county in the northwest corner of Arizona Territory that existed from 1865 until 1871, at which point most of the area was transferred to Nevada. The remainder was merged into Mohave County. The majority of the territory is now in Clark County, Nevada, which includes the city of Las Vegas. Due to the transfer of most of the county's land to Nevada, Pah-Ute is sometimes referred to as Arizona's "Lost County".[1] Pah-Ute is a historic spelling of the tribal name Paiute.