12hr road ultramarathons in North America

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

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

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

Timed ultramarathon featuring 12-hour and 24-hour options on a one-mile loop with full aid station support and space for personal setups

Daytime 12-hour, 6-hour, and 3-hour individual runs plus team relays, now part of the RUTS running series

One-mile paved loop on scenic university campus, spacious accessible lanes, grassy tent areas, abundant aid stations, and gymnasium facilities

Track-based ultra at Newport High School featuring 24-hour, 12-hour, and 50K distances, with 125 laps marking the 50K finish

Scenic Colt State Park loops with pavement, rooty trails, and grass; mostly flat terrain, waterfront views, frequent aid stations, summer heat challenge

Demanding 1.1-mile loop with 140 feet of elevation gain per lap, steep climbs on Hogsback Lane, a mix of paved and singletrack in Rocky River Reservation

Technical single-track and double-track trails along Unami Creek, with rocks, roots, mud, varied elevation, and scenic woodland terrain at Camp Hart.

Urban loop in central London with mild elevation changes, certified course, city scenery, and supportive atmosphere for ultra-distance performance

Short-loop .33-mile course around baseball park concourse, 24-hour format, open breaks, overnight atmosphere with movies and activities

Endurance challenge spanning daylight hours, designed for participants to push physical limits from sunrise to sunset

Flat, paved loop at Hainesport Township Park with 12-hour, 24-hour, 48-hour relay, and 100-mile options; continuous counter-clockwise running

Loop-based timed ultra in Wisconsin’s Southern Kettle Moraine Forest, with solo or relay laps shaped by endurance, pacing, and strategy.

Scenic Arkansas Bend Park routes overlooking Lake Travis, single-track and wide trails, moderate elevation changes, autumn foliage, night running sections

Scenic winery course with 24 hourly 5K loops, varied terrain from hard-packed dirt to sand and mud, winding through vineyard rows and around two lakes

Looped course on the Lake Ontario State Parkway Trail with accessible paths, dietary-sensitive aid stations, and lakeside scenery

2.25-mile loops on pavement, gravel, and grass at Malabar Farm State Park, with historic farm views and an atmospheric, haunted touch after dark.