Lean Horse Ultra

The Lean Horse Ultra Marathon is an annual ultra-running event held in August in the Black Hills of South Dakota, centered around the scenic George S. Mickelson Trail. Established in 2005, it offers multiple race distances including 100 miles, 50 miles, 30 miles, and 20 miles, along with a 100-mile relay and a unique 30-mile Black Hills CrossFit Edition for singles and teams. The course features crushed limestone surface with gentle, extended climbs due to its location on an old railroad bed. Hosted in the town of Custer, the race is known as one of the best non-technical and most scenic rails-to-trails courses in the U.S., with typical August temperatures ranging from 53 to 79 degrees Fahrenheit. Visit the organization's website for the most recent information.