September ultramarathons in Colorado, United States

30-leg road relay route from Idaho Springs to Buena Vista, traversing Guanella, Georgia, and Fremont passes with varied terrains and mountain views

Historic mining district course with ascents to Miners Creek, scenic trail descents, landmark passages, and strict pace cutoff times

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

Scenic, flat 1.05-mile loop with ultra-distance options and generous time limits, designed for fast times and all experience levels

Overnight team relay across 165 miles from Idaho Springs to Buena Vista, traversing Guanella, Georgia and Fremont Passes on scenic single track trails.

Rolling hills, golden aspen groves, expansive mountain views, and varied terrain on a challenging 50K trail course in Granby, Colorado

Point-to-point mountain course over scenic singletrack and dirt paths, exceeding 13,000 feet elevation with more than 6,500 feet of climb through Clear Creek’s,

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

Scenic 0.82-mile loop at 7,240 feet on the Palmer Divide, surrounded by mountain views; community-focused 24-hour ultrarunning event

Rugged decommissioned roads and newly reopened trails from La Veta, with panoramic views of dikes, buttes, and the Spanish Peaks

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

High alpine vistas and desert-style singletrack, 4,000 feet of climbing, scenic forest roads, and views of the Collegiate Peaks near Buena Vista, Colorado

High-alpine 50k with a 7,000-foot climb to 13,150 feet, sweeping Sawatch Range views, panoramic singletrack, and miles on the Colorado Trail.

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