50K October ultramarathons

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

Scenic mountain and countryside routes in the Serra d'Arga region with varied terrain and support from local villages

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

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

Three-loop 50K on North Georgia singletrack, with 5,000 ft of climbing, rocky ascents, technical stretches, stream crossings and waterfalls.

Rugged, remote trails through Shawnee State Forest with steep elevation, untouched wilderness stretches, and demanding technical terrain

Single-track woodland trails of Thunder Bay, 50km course through forested landscapes and varied terrain, community atmosphere, finisher medals

Out-and-back 50K on rolling, hilly trails through Epping Forest’s ancient woodlands and varied ecosystems, starting at Wanstead Flats

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

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

Flat course through St. Croix State Park, forest and prairie trails, Kettle River views, historic fire tower climb, generous cutoff times

Multiple-loop 50K course through Coopers Rock woodlands, with 687 feet elevation gain per 10K segment and a sustained Category 4 climb