October ultramarathons in United States (Southwest)

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

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

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

50- or 100-mile clockwise loop around Prescott, linking standout singletrack and backcountry trails across rugged central Arizona terrain

Rocky ascents and descents along shaded and open trails with lake views at Dana Peak Park; single-loop courses with minimal trail repetition.

Colorado fall colors, views of Pikes Peak, Lovell Gulch climbs, Rampart Range Road, singletrack near Rampart Reservoir, National Forest mountain vistas

Three-loop course through Cuyamaca Rancho State Park, summiting Cuyamaca Peak, circling Oakzanita Peak, and running PCT segments with desert views.

Diverse and challenging dirt and single-track trails, panoramic vistas, moderate elevation gain of 1,930 ft (50km) and 4,250 ft (100km)

Expansive Castle Rock trails and Ridgeline Open Space, soft single and double track, scenic butte views, and optional 200-step Challenge Hill finish

Rocky out-and-back 50K course through Bear Valley and Lake Spaulding, steep Signal Peak ascent, panoramic river canyon views, technical terrain

Gold country landscapes, South Fork Yuba River views, forested single-track, fire roads, off-trail sections, and historic town passages

Rugged coastal trails over dramatic cliffs and pristine beaches, with ocean views along the "Mountain of Gold" route

50-mile route from Norco to Huntington Beach, traversing diverse Southern California landscapes with scenic beauty and rugged terrain

Mountain routes near Los Angeles featuring Big Bear Lake views, Sugarloaf Mountain ascents, and descents into Siberia Canyon