Fort Peck Indian Agency
The agency is responsible for 12,000 Assiniboine and Sioux enrolled tribal members and the reservation contains about 2,094,000 acres of land within its exterior boundary. There are about 939,165 acres of tribal and allotted surface trust acreage that includes Turtle Mountain Public Domain lands.
- "Fort Peck Agency". Bureau of Indian Affairs. Retrieved 2011-02-05.
- Military history of the United States. "Major Charles B. Lohmiller, known as Hum-Pa-Zee (Sioux for "Yellow Shoes") served at the Fort Peck Indian Agency, Montana, during 1893-1917, and was Superintendent during 1904-17. Reveals Lohmiller as a man with an unapproachable, ..."
- Kenneth D. Shields, Jr. (1998). Fort Peck Indian Reservation. Arcadia Publishing. ISBN 0-7385-4827-8. "Horses Ghost was another one of the Sioux leaders who accompanied Major Charles B. Lohmiller"