Mines Of Spain 100 - Dubuque, IA

Mines of Spain 100, held in Dubuque, Iowa, offers 100-mile and 100-kilometer ultramarathons on October 17-18, 2025. Set in the driftless region’s bluffs, prairies and forests above the Mississippi River valley, it delivers a true Midwest trail experience. The course is described as a ~20‑mile loop featuring a mix of steep technical single-track, wide rolling dirt, and prairie double-track with additional scenic sections, designed to challenge and inspire runners of all levels—likely repeated to reach the 100‑mile/100‑km distances. The event emphasizes a grassroots, well-organized feel, supports area trail groups, and donates proceeds to Mines of Spain park for trail maintenance. Visit the organization's website for the most recent information.