December ultramarathons in United States (East)

Technical multi-lap course through Oak Mountain State Park, starting and finishing by Tranquility Lake

1.1-mile loop with 340 feet of climbing per lap, steep ascents, runnable sections, and a field descent on double track logging road

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

Two-mile looped trail along the Chattahoochee River with self-serve aid stations and a community-focused, no-frills atmosphere

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

Single track trails spanning cypress swamp bridges, hardwood forests and piney woods, with unexpected elevation changes for Louisiana

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

Trail race through rolling hills and hardwood forests, 12.7-mile loop with 2,300 feet of elevation gain per lap on a course normally closed to the public.

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.