Thumbs Up Vertical Challenge

The Calarat Challenge Trail Running Festival takes place in Jamestown, Colorado, at the Cal-Wood Education Center, a nonprofit dedicated to outdoor education. Held over Labor Day weekend, the event features multiple trail races including a half marathon, 10K, 5K, Kids 1K, and combination races like..

American Heroes Run takes place in Longmont, Colorado, on a flat, fast loop course of about 1.05 miles. The event features multiple distances, including a 100-mile race (with a 30-hour cutoff), a 24-hour option, marathon, half-marathon, 9.11-mile, and 5K, plus shorter time-limited runs. The atmosphe..

Black Squirrel Half Marathon is a trail race held at Lory State Park, northwest of Fort Collins, Colorado, with the start and finish at the Soldier Canyon Picnic Area in Bellvue. The 13.5-mile course tour climbs about 1,500 feet to a west ridge around 7,000 feet, then descends and follows roughly 4...

Nestled in Old Town Nederland, Colorado (elevation around 8,236'), NedNed Trail Fest offers a long-running trail challenge with three race options: a Half Marathon (about 13.3 miles with roughly 1,408 feet of elevation gain on dirt roads and single-track trails), a 10K (about 6.3 miles on dirt roads..

Red Feather Trail Jamboree is a three-day trail running weekend held near Red Feather Lakes, Colorado, starting from the Ben Delatour Scout Ranch. Runners can tackle three distances: 50 miles (≈8,500 ft of gain), 50K (≈4,200 ft), and a Half Marathon (≈1,700 ft), with a 3-day Challenge totaling about..

Estes Epic is a multi-event trail challenge held in Estes Park, Colorado. The weekend features a 50k bike race, a 50k trail run, a Heavy Half Marathon, and the all-in Epic Double (50k MTB and 50k Run). After a six-year break, the race returns with remote, rugged terrain, single-track trails, steep c..