Plentywood is located in the Northeast corner of the state and has served as a trading post for the people living in that part of the state. At the site of present-day Plentywood, Sitting Bull and his Sioux people surrendered to the U. S. Army after living in Canada for five years. The Outlaw Trail crossed into Canada north of Plentywood. Rustlers moved their stolen cattle and horses along this passage across the border. Butch Cassidy named the trail and established a rest station in the Big Muddy Valley, west of Plentywood. This area was 'the Old West' legend.