100K April ultramarathons in United States (South)

Repeated loops on private mountain trails, with relentless climbs, long switchbacks, and a remote, rugged feel in the Leatherwood Mountains.

Fully dirt out-and-back course along the New River and Chestnut Creek, with smooth, flat terrain and steady runnable miles.

Soft crushed gravel and dirt roads through Wheeler Wildlife Refuge, featuring birdwatching, wildflower spots, and multiple-loop endurance formats

Technical trails and rolling double-wide paths across the Cohutta Mountains, 5,000 feet of elevation gain, clockwise and counter-clockwise looping, Pinhoti deto

Rugged singletrack loops on Uwharrie and Dutchman's Creek Trails, steep elevation, scenic vistas, mixed daylight and nighttime running options

Demanding out-and-back on the Cumberland Trail with rugged singletrack, steep climbs and descents, and nearly 12,000 feet of gain.

Fast, flat, USATF-certified downtown loop with 12- and 24-hour options, festive atmosphere, food trucks, music, and special buckle for 100 miles

Firm sand beachfront loops with coastal views, 10-mile out-and-back sections, ocean-side route for both 100k and 50k distances

Point-to-point route from Kennesaw Mountain to Stone Mountain, featuring two summit climbs, single track trails, and Atlanta city landmarks

Four 15.5-mile loops through New River Gorge with technical river crossing, waterfalls, and 2,400 feet of elevation gain per loop