December ultramarathons in United States (East Coast)

Flat, sea-level loops with minimal elevation gain and a lively event village atmosphere

Challenging 2.5-mile loop every 45 minutes, elimination format with no breaks, last runner standing wins, endurance-focused test

Technical 10.5-mile loop with rolling hills and diverse terrain through Caloosahatchee Regional Park’s scenic Green, Black, and Blue trails

Alpine mountain loops on Dartmouth Skiway’s rugged slopes, steep climbs, and varied terrain with significant elevation changes in a wintry setting

100-mile course on a 7.2-mile loop amid long leaf pines and palmettos, gentle 225-foot elevation per loop, wildlife sightings, and illuminated night sections

Flat rail trail with gentle inclines, sub-1500 feet elevation gain, downtown Farmville start, High Bridge crossings, generous 100k cutoff

Smooth, rolling singletrack on a no-repeat 50K with wooded loops, changing scenery, and around 1,600 feet of elevation gain.

Out-and-back loops on the Tower Trail in Sleeping Giant State Park, 600'+ elevation gain per loop, winding gravel paths, repetitive ascents and descents

Rugged technical trails with roots, rocks, steep elevation changes, and intermittent Boston skyline views in classic New England woodland

Mostly trail route with 4,000 ft elevation gain, rocky technical sections, waterfall views, and a final steep canyon ascent in distinctive Georgia scenery.

Looped single-track trails with roots, rocks, rolling hills, short technical stretches, and fire road sections through northern Virginia

Cross-country 40-mile course over rolling hills and lush trails at Shakori Hills Community Art Center, featuring scenic terrain and a communal atmosphere

Hourly looped course elimination format, continuing until only one runner remains

Multi-hour trail run and mountain bike loops through Camp Grier’s wooded trails, festive atmosphere, and community fundraising in Old Fort, NC

Brutally steep backyard ultra loop at Amicalola Falls: East Ridge descent, Mountain Laurel section, and the 605-step AT Approach climb.

Muddy trails, rain-soaked terrain, and a 24-hour course featuring event traditions

Beachside 6-hour ultra with ocean sunrise views, firm sand loops, small field, and dedicated volunteer support at each aid station

50k and 100k winter ultras on a relatively flat rail trail, with gentle inclines, low elevation gain, and two crossings of High Bridge

Technical singletrack winding through rocky outcrops, dramatic cliffs, and winter landscapes in Hanging Rock State Park’s mountainous terrain

Certified 50K on a fast multi-loop out-and-back course, with smooth pacing rhythm and start/finish aid access each loop.