6hr ultramarathons in Illinois, United States

Half-mile pine forest loop in Lowell Park, continuous 6, 12, or 24-hour format with self-supported setup and solo or team options

Timed 3- or 6-hour run on a 1-mile loop around Watershed Nature Center, evening hours requiring a light source, limited to 140 participants

Challenging 12-hour last runner standing on a 4.1-mile rugged trail loop amid summer heat at Comlara parks, testing endurance, pacing, and strategy

Scenic 1-mile paved loop in a 58-acre city park, rotating hourly challenges, 6- or 12-hour format, solo or relay options, central aid station and vendor

1.2-mile loop course, flexible durations up to 24 hours, single aid station, relaxed community atmosphere, nighttime running with quiet hours enforced

2.07-mile gravel and concrete loop at Arrowhead Lake Campground with minimal elevation, designed for speed and high mileage in Johnston City, IL.

Cross country trails winding through Caldwell Woods and Bunker Hill, 5 km loops on grassy or paved terrain, ultra and team options, winter forest setting

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

Fast, flat 1.3-mile loops on paved pedestrian paths within Herrin Sports Complex, open grounds backdrop, six-hour timed endurance format

Successive lap format on winding trails with strict hourly cutoffs, testing stamina and recovery management