Lean Horse Ultra

Custer, United States • 15-16 Aug 2025

The Lean Horse Ultra Marathon, held annually in August in Custer, South Dakota, offers a variety of race distances including 100 miles, 50 miles, 30 miles, 20 miles, and a unique 30-mile Black Hills CrossFit Edition with relay options. Established in 2005, the event takes place on the scenic George S. Mickelson Trail, known for its crushed limestone surface and gentle climbs.

The race is recognized as one of the best non-technical courses in the U.S. and is the 33rd sanctioned 100-mile race in the country. Participants can enjoy the beautiful Black Hills while competing in this challenging event. Visit the organization's website for the most recent information.

Race information

100 mi
100 Mile
50 mi
50 Mile
30 mi
30 Mile
30 mi
30 Mile Black Hills Crossfit Edition - Singles
30 mi
30 Mile Black Hills Crossfit Edition - Teams of 3
30 mi
30 Mile Black Hills Crossfit Edition - Teams of 6
20 mi
20 Mile
Visit the organization's website for the most recent information.
Trail runs nearby