Bighorn River Wind River Canyon near the town of Thermopolis. From there, the river flows through the Bighorn Basin in north central Wyoming, passing through Thermopolis and Hot Springs State Park. At the border with Montana, the river turns northeast, and flows past the north end of the Bighorn Mountains, through the Crow Indian Reservation, where the Yellowtail Dam forms the Bighorn Lake reservoir. The reservoir and the surrounding canyon are part of the Bighorn Canyon National Recreation Area. The Little Bighorn River joins the Bighorn near the town of Hardin, Montana. Approximately fifty miles farther downriver, the Bighorn River ends where
Battle of the Little Bighorn in a series of conflicts known as the Sioux Wars, which took place from 1854-90. While some of the indigenous people eventually agreed to relocate to ever-shrinking reservations, a number of them resisted, at times fiercely. On May 7, 1868, the valley of the Little Bighorn became a tract in the eastern part of the new Crow Indian Reservation in the center of the old Crow country. There were numerous skirmishes between the Sioux and Crow tribes so when the Sioux were in the valley in 1876 without the consent of the Crow tribe, the Crow supported the US Army