American Bottoms 100

The American Bottoms 100 is a unique road ultramarathon held in Columbia, Illinois, near St. Louis, Missouri. The event offers two distances: a 110-mile race and a 55-mile race.

The course follows scenic levees and hardball roads along the Mississippi River through the historic American Bottom region, including landmarks like Piggott's Fort and Fort de Chartres. The mostly flat and fast course features 700 to 1,400 feet of elevation gain, generous cutoff times, and multiple aid stations (8 for 55 miles, 17 for 110 miles). It provides a friendly atmosphere ideal for first-time hundred-milers or those seeking a personal best. Visit the organization's website for the most recent information.