Beaver Creek County Park Campgrounds Professional Review and Guide
"Most people probably haven’t heard of Fort Assinniboine, but when it was built in 1879 near the Milk River, it was the largest fort west of the Mississippi, encompassing all of the Bears Paw Mountains. The fort was built in response to concerns about Indian attacks after General Custer’s defeat at Little Big Horn in 1876 and Chief Joseph’s surrender in 1877 at Bear Paw Battlefield, 37 miles southeast.
Before the fort was abandoned in 1911, General John Pershing served here as a lieutenant, and two companies of the 10th Cavalry “Buffalo Soldiers” trained here prior to their service in the Spanish-American War. Some of the fort’s buildings still stand 6 miles southwest of Havre on US 87, and walking tours are available. After the fort was abandoned, much of the land was designated as the Rocky Boy’s Reservation, and the section that ultimately became Beaver Creek County Park bounced between the federal government, the state, and the city of Havre until it was finally established as a Hill County park in 1948."