WordNet sense 1 (a river that flows from northern Wyoming into the Bighorn River in southern Montana; site of Custer's Last Stand):

Little Bighorn River, Little Horn

WordNet sense 2 (a battle in Montana near the Little Bighorn River between United States cavalry under Custer and several groups of Native Americans (1876); Custer was pursuing Sioux led by Sitting Bull; Custer underestimated the size of the Sioux forces (which were supported by Cheyenne warriors) and was killed along with all his command):

Battle of Little Bighorn, Battle of the Little Bighorn, Custer's Last Stand