American Bottoms 100

American Bottoms 100 is a road ultra held in Columbia, Illinois, just outside St. Louis. It offers 110-mile and 55-mile options along a flat, fast course following the Mississippi River through the historic American Bottom.

The route loosely traces the American Discovery Trail and the Kaskaskia–Cahokia Trail, with sunrises over Illinois bluffs as you run on levees and backroads toward the confluence of the Kaskaskia and Mississippi. Runners pass sites like Piggott's Fort and Fort de Chartres. The event features generous cutoffs, abundant aid stations (17 on 110, 8 on 55), and a friendly, low-entry-fee, no-frills atmosphere; ideal for a first hundred or a personal best. Visit the organization's website for the most recent information.