March ultramarathons in Illinois, United States

Flat, fast 113-mile and 56-mile road ultra along the Mississippi, with pavement, gravel, levees, backroads, and historic river landmarks.

Looped course on paved paths with rolling hills, timed format, basecamp aid station, and crew support permitted

Single-track woods loop with alternating directions, 166 feet of elevation gain per lap, a few road crossings, and a 33.75-mile total distance

Chicago North Side lakefront 50K with three out-and-backs, mostly gravel and some asphalt, on one of North America’s flattest courses.