Mines Of Spain 100 - Dubuque, IA
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Mines of Spain 100, Dubuque, IA, October 16, 2026
The Mines of Spain 100 is a trail ultramarathon organized by Sun Trail Running in Dubuque, Iowa on October 16, 2026. The event offers multiple distance options on a looped trail course.
- 100 mile : five loops of an approximately 20 mile course
- 100 kilometer : three loops of an approximately 20 mile course
The course is an approximately 20 mile loop that starts and finishes at Louis Murphy Park and spends most miles inside the Mines of Spain Recreation Area. Trails include dirt, grass and rock surfaces with a few short pavement connectors. The route passes overlooks of the Mississippi River, traverses around Horseshoe Bluff, and moves through grass prairies and hardwood forests. Trail conditions range from steep and technical sections to flat single track and rolling grassy stretches.
Elevation gain is roughly 2,800 feet per loop, totaling about 14,000 feet for the 100 mile race and about 8,400 feet for the 100 kilometer race. Time limits are 33 hours for the 100 mile distance and 23 hours for the 100 kilometer distance.
Registration is scheduled to close on October 1. When capacity is reached a public waitlist is maintained and entrants are invited in order. Runners may switch distances under stated deadlines; switching up has a one month before race day deadline. Partial refunds and deferrals are available with set deadlines: 100 percent deferral or 50 percent refund by June 30, and 75 percent deferral by August 31. Deferral credits are valid for two years and are not transferable. The race reserves the right to modify the course or cancel the event for safety or trail condition concerns; such changes may be made without a refund. Visit the organization's website for the most recent information.
