American Bottoms 100
Always double-check with the organizer's website! This page may contain affiliate links.
Event overview
The American Bottoms 100 is a road ultramarathon held in Columbia, Illinois, on Saturday, March 21, 2026. The event is based in Columbia, IL, just outside St. Louis, Missouri, and follows sections of the Mississippi River and the historic American Bottom. The course follows parts of the American Discovery Trail and the Kaskaskia - Cahokia Trail and passes several historic sites, including Piggott's Fort, Fort de Chartres, and Prairie du Rocher. A 15% veteran and first responder discount is listed; a coupon code is required.
Distances and course details
- 110 mile
- 55 mile
The 55-mile race is a point-to-point course with about 700 ft of total elevation gain, 76% levees and 24% hardball road, and 8 aid stations. It has a 15-hour cutoff and an equivalent pace allowance of 16:21 minutes per mile.
The 110-mile race is an out-and-back course with about 1,400 ft of total elevation gain, 76% levees and 24% hardball road, and 17 aid stations. It has a 34-hour cutoff and an equivalent pace allowance of 18:32 minutes per mile. Visit the organization's website for the most recent information.
