Annual Custer State Park Buffalo Roundup – September 26, 2025 Watch cowboys and cowgirls as they roundup and drive the herd of approximately 1,300 buffalo. Not only is the roundup a spectacular sight to see, it is also a critical management tool in maintaining a strong and healthy herd. The Buffalo Roundup begins at 9:30 a.m. MT on September 26, with parking lots opening at 6:15 a.m. Be sure to arrive early if you want to pick your spot. Guests…