Mines of Spain 100

Mines of Spain 100 takes place in Dubuque, Iowa, on October 16, 2026. Two trail ultras share an 8 a.m. start: a 100-mile race and a 100K (62 miles). Both run in the Mines of Spain area on the Mississippi bluffs south of the city, and both give you the daylight of a mid-October Friday before the field spreads out into the night.

The 100K works well as a stepping stone for anyone who has finished a 50-miler and wants to spend a full day on the trail before committing to the full 100. The 100-mile race is a different commitment entirely: expect to run through the night, and expect the last quarter to be decided by your feet, your stomach and your willingness to keep moving. A 20-week build with high-volume weekends and a couple of night runs is the usual recipe.