The Tri-State Museum is a 4,000-square-foot, city-owned and -operated historical museum in Belle Fourche. Our museum focuses on the early pioneer, rodeo and Old West history of the region: western South Dakota, eastern Wyoming and southeastern Montana. It houses more than 5,000 artifacts, rodeo memorabilia, historical records, antiques, collectibles, fossils and other items. Our hours are 10 a.m.-4 p.m., Tuesday-Saturday. The Center of the Nation Monument is located right behind the museum.