August 15 – 16, 2025

RACE OVERVIEW

The Lean Horse Ultra Marathon is run in August every year in the Black Hills of South Dakota. It was first run in 2005. It features a 100-mile race, a 50-mile race, a 30-mile race, and a 20-mile race. The course is held on the George S. Mickelson Trail.

*30-Mile Black Hills CrossFit Edition Singles and relay teams of 3 or 6.

Course Overview

  • Surface: Crushed Limestone
  • Course: Mickelson Trail
  • Elevation Profile: Extended gentle climbs. This is due to the fact the course is on an old railroad bed
  • Hosting Town: Custer, South Dakota
  • Average August Daytime Temperature: High of 79 degrees.  Low of 53 degrees.

Fun Facts

  • 33rd sanctioned 100-mile race in the United States
  • Known as one of the best non technical courses in the United States
  • One of the most scenic rails to trails courses in the country

Learn about Custer, South Dakota

RACE OVERVIEW

The Lean Horse Ultra Marathon is run in August every year in the Black Hills of South Dakota. It was first run in 2005. It features a 100-mile race, a 50-mile race, a 30-mile race, and a 20-mile race. The course is held on the George S. Mickelson Trail.

*30-Mile Black Hills CrossFit Edition Singles and relay teams of 3 or 6.

Course Overview

  • Surface: Crushed Limestone
  • Course: Mickelson Trail
  • Elevation Profile: Extended gentle climbs. This is due to the fact the course is on an old railroad bed.
  • Hosting town: Custer, South Dakota
  • Average August Daytime Temperature: High of 79 degrees.  Low of 53 degrees.

Fun Facts

  • 33rd sanctioned 100-mile race in the United States
  • Known as one of the best non technical courses in the United States
  • One of the most scenic rails to trails courses in the country

Event Distances

Event Media

On Instagram

(#leanhorse100, #leanhorseultra, #leanhorse50, #leanhorse30, #leanhorse20, #BHCFe, #LHBHCFe)