50K January ultramarathons in United States

Lakefront trails through Arkansas Bend Park, skirting the Colorado River and limestone bluffs, with natural terrain and unique endurance formats.

Groomed forest trails on a three-lap loop, limited course marking with self-navigation, relaxed format with route flexibility

Dynamic loops at Shaffer Bend Park along limestone bluffs and the Colorado River, sun-bleached trails, lush scenery, and manageable elevation per loop

Looped trail course over sun-bleached limestone bluffs, riverside paths, and Colorado River views, with moderate elevation changes and stargazing opportunities

Scenic trail routes through Hacienda Hills with Bay Area views and challenging elevation at Almaden Quicksilver County Park

Scenic 6.2-mile trail loop at Bradley Palmer State Park, repeatable up to five times, on beautiful park trails with a relaxed, non-competitive atmosphere.

Shaded singletrack weaving through oak hammocks and classic Florida scenery in Withlacoochee State Forest

Rugged, root-laden single-track trails through Cameron Park’s valleys and hills, 450 feet of elevation gain per 8K loop, cool winter temperatures

Scenic rolling trails and winter conditions at Yankee Springs State Recreation Area; 50k course with frequent aid stations

Looped course with flexible lap totals and early start option, welcoming atmosphere to begin the year with fellow runners

Classic early-season New England trail ultra with deep regional roots and longstanding community tradition.

Scenic Willis River Trail loops with stream crossings, rolling hills, and a Bear Creek extension for the 50k option

Three-section winter course with open flat stretches, runnable dirt roads, and a technical but runnable finish; loop format with easy access between laps.

Out-and-back ultra across Catalina Island with rugged terrain, Pacific Ocean views, and possible bison sightings from start and finish in Avalon.

Rugged Texas Hill Country trails, rocky paths, thorny foliage, and technical terrain amid striking natural scenery

Rolling singletrack through saguaro-studded Sonoran desert, with the steep, rocky Goldmine climb and wide-open views in San Tan Mountain Regional Park.

Singletrack and jeep trail around Bonita Lakes, with roots, rocks, rolling hills, filtered tree views, and a downhill finish on Mardi Gras Trail.

Triple black diamond 50K ultramarathon on single-track trails through Veteran Acres and Sterne’s Woods, featuring a rugged winter landscape

50k around scenic Salem Lake: wide rolling dirt trail, brief paved section, quiet woods, shoreline views, and gentle terrain.

Western States trail route featuring No Hands Bridge, K2 training hill, single-track along American River, Robie Trail, Dead Truck, Goat Hill, and Overlook Hill