Mines Of Spain 100 - Dubuque, IA

Mines of Spain 100 : October 16, 2026, Dubuque, IA

The event offers two ultra distances based at Louis Murphy Park in Dubuque and using the Mines of Spain Recreation Area trails. Distances include:

• 100 miles
• 100 kilometers

The race follows a marked loop of about 20 miles that is repeated for each distance. Most miles are on dirt, grass and rock trails with short paved stretches at the beginning and end of each loop. The route passes scenic overlooks of the Mississippi River, goes around Horseshoe Bluff and travels through grass prairies and hardwood forests. Trail surfaces and terrain vary from steep and technical sections to flat dirt single track and rolling grassy trail.

Course metrics, timing and policies

Elevation gain is about 2,800 ft per loop, totaling about 14,000 ft for the 100-mile race and 8,400 ft for the 100k. Time limits are 33 hours for the 100-mile distance and 23 hours for the 100k. Registration opens January 1, 2026. Switching distances is allowed; switching up to the 100-mile race must be done one month before the event, while switching down is allowed through pre-race packet pickup. A public waitlist is used if the race reaches capacity. Partial refunds and deferrals are available under stated deadlines; pregnancy deferrals and a two-year deferral credit policy are included. The race may modify the course or cancel for safety or natural disaster, in which case registration fees are not refunded. Mile 90 Photography will provide photos for runners after the event. Visit the organization's website for the most recent information.