October ultramarathons in United States

Certified one-mile loop of pavement and crushed gravel at Sussex County Fairgrounds; flat, fast and highly runnable for 50K to 100 miles.

One-mile loop on grass and mulched paths, winding around ponds and open fields with light elevation gain and continuous on-course support.

Mountain ultramarathon along the Wasatch Front with 20,869 feet of vertical gain, rugged singletrack, exposed ridges, and scenic canyon trails

One-mile hard-packed dirt loop with direction changes every four hours, frequent aid stations, and personal camp support throughout timed ultra options.

Rugged 100-mile route through the San Gabriel Mountains' primitive wilderness, featuring rough terrain and scenic, largely untouched backcountry

214-mile loop race around Mammoth Lakes, spanning the Eastern Sierra with 9,346 m of climbing over five days and a 108-hour cutoff

Night trail loops under the brightest full moon, marked courses of 3.3 or 4.17 miles, 8-hour lap challenge and 12-hour Last Runner Standing format

Woodland course through Roosevelt Forest, tree-lined trails and natural scenery in historic Stratford, CT

24-hour race with accurate timing, emphasizing competition, personal achievement, and camaraderie on a runner-designed course

3.1-mile rolling hill loop with single-track, wide trails, grassy sections, bridge crossings, 24-hour format, heated indoor bathrooms, on-site camping

Rugged Pisgah singletrack featuring iconic trails like Black Mountain, Turkey Pen Gap, Laurel Mountain, and Pilot Rock

Challenging 50k course with 6,300 feet of elevation gain, single and double-track terrain, and a summit ascent on Montana's Whitefish Trail

Rocky bluffs, sandy beaches, old-growth rainforest, and headlands with Pacific Ocean views in the Cape Perpetua National Scenic Area

Historic Uravan Ballpark start and finish, abandoned mining roads, desert single-track, canyon passages, slick-rock, and river confluence views

Rugged 50k trail course with creek crossings, steep climbs, and about 750 feet of elevation gain per loop through scenic Swiss Valley Nature Preserve

Flat, fast point-to-point course along the scenic Hennepin Canal from Sterling to Colona, featuring historic locks, lift bridges, and autumn farmland views

Interconnected North and South shore trails, rolling hills, technical and smooth terrain, roots and rocks, tree canopy and exposed sections in Shawnee Mission  

360-degree mountain views in Hartman Rocks Recreation Area, technical slickrock, smooth singletrack, doubletrack, and sagebrush hills