Runners crossing a wooden bridge on the Mickelson Trail

Lean Horse Ultra Marathon

July 30–31, 2027 · Custer, South Dakota

The Lean Horse Ultra Marathon, held on the Mickelson Trail in the Black Hills of South Dakota, features the following events: 100 Mile, 100 Mile Relay, 50 Mile, 30 Mile, 20 Mile, and 30 Mile Black Hills CrossFit Edition

RACE OVERVIEW

Early Bird Pricing Open Now
Standard Pricing January 10th 2027
Late Pricing July 1st 2027

Registration Closes July 16th 2027

The Lean Horse Ultra Marathon is run in late July 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 Late-July 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

Event Distances

100 Mile

100 Mile Relay (up to 5 runners)

50 Mile

30 Mile

20 Mile

30 Mile Black Hills CrossFit Edition

Singles
Team of 3
Team of 6

Event Media

On Instagram

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

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