Chouteau County, Montana in the context of Rocky Boy's Indian Reservation

Rocky Boy's Indian Reservation (also known as Rocky Boy Reservation) is one of seven Native American reservations in the U.S. state of Montana. Established by an act of Congress on September 7, 1916, it was named after Ahsiniiwin (Stone Child, incorrectly originally translated as Rocky Boy), the chief of the Chippewa band, who had died a few months earlier. It was established for landless Chippewa (Ojibwe) Indians in the American West, but within a short period of time many Cree (nēhiyaw) and Métis were also settled there. Today the Cree outnumber the Chippewa on the reservation. The Bureau of Indian Affairs (BIA) recognizes it (and the tribe) as the Chippewa Cree Reservation.

The reservation is located in Hill and Chouteau counties in north central Montana, about 40 miles (64 km) from the Canada–U.S. border. It has a total land area of 171.4 square miles (444 km), which includes extensive off-reservation trust lands. The reservation reportedly has 3,323 enrolled members, 55% of the total 6,177 enrolled members in the tribe.

Asiniiwin, translated Rocky Boy or Stone Child, was an important Ojibwe leader who was chief of a band in Montana in the late 19th century and early 20th century. His advocacy for his people helped gain the establishment of what is called Rocky Boy's Indian Reservation in his honor. Formed from part of Fort Assiniboine, which was closed, it is located in Hill and Chouteau counties in north central Montana.