Rocky Mountain House, town (1991 pop. 5,461), S central Alta., Canada, at the foot of the Rocky Mts. and the confluence of the North Saskatchewan and Clearwater rivers. Founded in 1799 as a fortified post of the North West Company in Blackfoot country and known as Blackfoot post, it was taken over (1821) and operated by the Hudson's Bay Company until 1875. It is now the gateway to a big-game hunting area.