The Flathead inhabited the Bitterroot River Valley of southwest Montana in the early-19th century. The tribe depended fishing in the spring, on the women for root and berry foods during summer, on the men for deer and elk meat in late summer, and in the autumn they migrated eastward to hunt bison into the winter. Their plateau culture was transformed by plains traits related to horsemanship and organized bison hunting. A semi-hereditary chief governed with the assistance of a tribal war leader, a council of lesser chiefs, and an informal police.