6hr ultramarathons in United States

Nighttime endurance laps on an illuminated dirt horse track at Harrison County Fairgrounds with continuous chip timing and flexible distance

Scenic Kennesaw Mountain course passing historic sites, wooded trails, gravel, and asphalt, featuring sunrise and sunset views along an 8-mile out-and-back loop

Scenic 1.9-mile loop at Notchview with a 0.2-mile climb, rolling single and double track, open fields, and cross-country ski trails

Paved 1-mile loop with gentle elevation, direction changes, and a fully stocked aid station at the start/finish area

Looped nighttime miles on runnable single-track dirt trails through cedar and hardwood forests along the Duck River, glowing with reflective markers

Steep switchbacks in lush forests, ski slopes with panoramic vistas, and expansive fields across a 5-mile loop with 810 feet of elevation change

Rolling grassy hills on a compact cross country loop with team relay format, dusk headlamps required, and awards for most laps completed

1.776-mile loop through historic Putnam Memorial State Park, featuring multiple timed race options in a landscape tied to Revolutionary War history

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

Crushed limestone loops circling Miola Lake with well-stocked aid stations in a low-key, supportive ultramarathon setting

Flat, open field trail designed for speed, minimal obstacles, challenging heat, personal fueling spots, and a communal post-race food spread

Six-hour endurance format at Greenbury Point, with Chesapeake Bay waterfront views and an exposed coastal setting.

Shaded crushed gravel loop along the Big Piney River, 6-mile circuit with a notable hill, festive summer setting near Old Route 66

Flat 1.25-mile paved loop on a former military base with asphalt, concrete, a brief gravel section, and shady pine trees

Scenic alpine 10K loop with 1,546 feet of vertical gain per lap, technical trails through aspen groves and meadows at Powderhorn Mountain

Shaded woodlands loop on mixed surfaces in Route 66 State Park; flat, fast course with summer heat, night running, and main aid station support

Overnight looping relay and ultra at Kroger Field, with a paved course and a grassy, trail-like section for added variety.

Challenging dirt trails and singletrack loops through Franke Park, four or eight hour solo or team formats, event village amenities

Night trail loops on undulating 3.2-mile course at Cedar Ridge Preserve, featuring wooded terrain, varying elevation, and multi-hour endurance format

Rugged, heat-defined 24-hour and 48-hour ultra with smart pacing, cooler nighttime hours, and a laid-back, communal atmosphere