December ultramarathons in United States (New England)

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

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

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

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