100 Mile Races in South Dakota
As of November 1, 2026, Crewable lists 1 upcoming 100 mile race in South Dakota in July 2027. It is Lean Horse Ultra Marathon on July 31, 2027 in Custer. Registration is open.
Sources: UltraSignup, RunSignUp, UTMB, race organizers and race websites
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Quick answers
What is the next 100 mile race in South Dakota?
Lean Horse Ultra Marathon, on Saturday, July 31, 2027, in Custer. Distances: 100 mi, 50 mi, 30 mi.
How many 100 mile races in South Dakota have open registration?
It lists registration as open as of November 1, 2026.
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