The Arapaho are a tribe of Native Americans originally from Colorado and Wyoming in the American West. The Arapaho were close allies with the Cheyenne and loosely allied to the Lakota and Dakota, and they resisted the United States' expansion, with Big Mouth and Black Horse being two leaders of the tribe. The Arapaho were later defeated by the US Army, and they moved into reservations in the 1870s. Today, there are 10,861 Arapahoes in the USA, living in Colorado, Oklahoma, Wyoming, and Nebraska.