The name Ten Sleep comes from the Sioux Indians who frequently stopped in this valley during their travels between a permanent camp along the Clarks Fork River in Montana and another one along the Platte River. Halfway between the two was Ten Sleep, so-named because they measured distances in the number of nights it took to get to a place. The town of Ten Sleep was established as a trading center for the Scottish and Irish sheepmen who came here in the 1890s.