American Bottoms 100

WELCOME TO THE AMERICAN BOTTOM

This is a unique road ultra on a beautiful course, following the Mississippi River, as you run through the historic American Bottom. Race headquarters is in Columbia, Illinois just outside of St. Louis, Missouri. The race offers a 110 mile and a 55 mile option.

The course will loosely follow the American Discovery Trail and the Kaskaskia - Cahokia Trail (Illinois' first road). You’ll watch the sun rise over the Illinois bluffs while running on levees and deserted backroads, from Columbia to the confluence of the Kaskaskia and Mississippi Rivers. You’ll make your way through many historic sites, including Piggott's Fort, Fort de Chartres, and the town of Prairie du Rocher.

This is a flat and fast course with generous cut off times, plenty of aid stations, and a friendly atmosphere. It will make a great first hundred miler, or a chance for you to set a new personal record at this distance. So, if you're interested in a no frills ultra with a low entry fee, then come test yourself this spring on the American Bottom.

110 MILE

6:00 a.m. Start. Saturday March 21st, 2026

4:00 p.m. Finish. Sunday March 22nd, 2026

34 hour cut-off

18:32 minute / mile pace

1,400 ft. of elevation gain total

Out & back course

76% levees / 24% hardball road

17 Aid Stations

55 MILE

Saturday March 21st, 2026

7:00 a.m. Start

10:00 p.m. Finish

15 hour cut-off

16:21 minute / mile pace

700 ft. of elevation gain total

Point to point course

76% levees / 24% hardball road

8 Aid Stations