Intermediate ultramarathons in Colorado, United States

High-altitude trails above 10,000 feet through alpine meadows, ghost towns, and mining relics, with sweeping views of the South Park Valley and Decalibron peaks

High-altitude 50-mile out-and-back over dirt, rocks, and mud with challenging climbs, fast descents, and views of Leadville’s historic mining district

Rugged high-altitude ultramarathon through State Forest State Park, with alpine lakes, rocky ridges, remote trails, and 14,500 feet of elevation change

50-mile route from Bear Creek Regional Park through High Drive, Cheyenne Canon, and notable landmarks including Seven Bridges and Helen Hunt Falls

Technical trails across the flat-topped Grand Mesa, high-altitude forests, alpine meadows, lakes, and streams

High-altitude courses over 10,600 feet, technical trails and remote forest service roads, striking mountain views, and challenging wilderness terrain

Technical high-altitude course through the San Juan Mountains with steep, rocky terrain, exposed ridgelines, and significant elevation gain above Telluride

Out-and-back 100-mile ultramarathon through high-altitude Rocky Mountain terrain, featuring Hope Pass, Sugarloaf, Powerline climbs, and 18,000 feet of gain

Point-to-point ultramarathon across Colorado’s rugged Elk Mountains, tracing historic backcountry trails with high-elevation alpine vistas and technical terrain

Mountain routes through Routt National Forest and Emerald Mountain, signature climbs and descents, autumn scenery, 9,000–22,000 feet of elevation gain

High-country ultramarathon with 50 Mile and 50K routes on singletrack and dirt roads, challenging climbs, moose-filled forests, and sweeping mountain views

High-altitude ultramarathon across Crested Butte’s demanding trails, with sweeping Gunnison National Forest views, wildflower meadows, and fall foliage

Rolling terrain on the Rainbow Trail beneath the jagged peaks of the Sangre de Cristo mountains, along the Southern Colorado Rockies wilderness boundary.

Rugged 50k trail route with significant elevation gain, technical terrain, and alpine vistas near Rocky Mountain National Park

Diverse and challenging dirt and single-track trails, panoramic vistas, moderate elevation gain of 1,930 ft (50km) and 4,250 ft (100km)

Singletrack ultrarunning through montane forests, golden aspens, red rock formations, panoramic city skyline views, and vibrant fall scenery near Denver

Scenic Royal Gorge Mountain Park singletrack with Tunnel Drive tunnels, steep climbs, big vistas, and a crossing of the highest bridge in the US.

Western Slope views along Road 18 Trails, featuring a mix of smooth and technical singletrack on a scenic, demanding course in Fruita, Colorado.

Flowing singletrack, mesa climbs, red slickrock cliffs and buttes, with overlooks above the Colorado River and wide-open desert views.

Ultra-distance courses along the Poudre River Trail from Watson Lake to Greeley, featuring scenic Northern Colorado landscapes and aid stations.