December ultramarathons in United States (Northeast)

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

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

Backyard ultra format on a 4.2-mile loop along the Schuylkill River Trail, hourly starts, elimination on failure to finish within the hour

50K and 50-mile road ultra on repeated 3.33-mile Prospect Park loops, with a spectator-friendly format and frequent aid access

Seven loop course with rolling hills, open fields, and New Jersey farmland; over 32 miles on 95% trails and double track in Holmdel Park.

2.45-mile loop with mixed trail and path, moderate elevation gain, minimal aid, variable New England weather, and classic low-frills ultrarunning format

2 to 3-mile loops on mostly gravel trails and camp roads with pirate-themed celebrations

Punishing trail loop with relentless climbing and steep, repeated laps, building to 6,400+ feet of elevation gain over 50K.

Paved 3.75-mile loop at Cooper River Park, mostly flat with gradual inclines and two notable hills, featuring water views and Philadelphia skyline

Single track trails with rolling elevation around Blue Marsh Lake, offering a manageable challenge for all experience levels

Ten 5K paved loops in Forest Park with limited traffic, possible snow, and flexible distance options on the Snowstorm Classic 5K route

Scenic 100k point-to-point route from Horseshoe Lake, featuring trail and road sections through state parks, lakes, and picturesque New Jersey towns

1.6-mile loops around Lake Wintergreen with 65 feet elevation gain per loop, supportive atmosphere, capped at 50 participants, all-weather event

2.2-mile loop course with lap format at Fleet Feet Mechanicsburg, annual event supporting Communities Rising initiatives for children in Southern India.