Trail Running calendar near Vail 2025-2026

Crested Butte Ultra, in Crested Butte, Colorado, features 50 Miler, 55K, and 35K formats. Runners traverse the Gunnison National Forest on single-track trails through mountain meadows and up to high ridges for wide-open vistas of wildflowers, mountain backdrops, and fall foliage. The event aims to f..

The Emerald Mountain Trail Run takes place in Steamboat Springs, Colorado, offering two race distances: a 12k (approximately 7.75 miles) and a 4-mile run. The scenic course starts at the base of Howelsen Hill and winds through aspen-lined single-track trails on Emerald Mountain. The event welcomes h..

The West Line Winder is a scenic trail running event held in Buena Vista, Colorado, featuring two race distances: a 50K (30.6 miles) with 4,000 feet of ascent and a 30K (18.1 miles) with 2,080 feet of ascent. The courses traverse buttery singletrack trails, forest roads, and some paved sections, set..

Golden Leaf Half Marathon, presented by ACG, is the bucket-list race hosted by the Ute Mountaineer and the City of Aspen. The half marathon (approximately 13.1 miles) starts at Fanny Hill in Snowmass and follows the Government Trail through scenic Aspen groves, finishing at Koch Lumber Park in downt..

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..

The Sawatch Ascent 50k is a challenging high-alpine trail race held in Nathrop, Colorado, showcasing the stunning Sawatch Range. Covering 33 miles with 7,000 feet of vertical gain, the course features a mix of 26 miles of singletrack, paved, and gravel roads, including 12 miles on the Colorado Trail..

14er Fest is a fall trail-running event in Buena Vista, Colorado, featuring two races: an 8.7-mile (14K) course and a 3.1-mile (5K) course. The 14K starts in Buena Vista River Park, crosses the Arkansas River, and climbs the Midland Hill Trail System for over 500 feet of elevation gain, offering pan..

Rocky’s Backyard Ultra is held at the YMCA of the Rockies Estes Park Center in Estes Park, Colorado. Runners must complete 4.167 miles in under one hour each lap, with the field reduced to a single finisher as the race continues until no others remain. The course loops around the boundary of RMNP on..

The Bear Chase Race Endurance Festival occurs at Bear Creek Lake Park in Lakewood, Colorado, offering 100K, 50 Mile, 50K, Half Marathon, 10K, and 5K (plus the Baby Bear 10K). The mostly dirt, single-track course is described as fast by trail/ultra standards and rewards sweeping mountain views with c..

Suffer Better Fall Trail Runs take place at Staunton State Park, just off Highway 285 near Conifer, Colorado. The event offers four distances: 50K, 25K, a 25K FishSlappers edition, and a new 5K. The course showcases CO’s best trails—lovely, flowing singletrack with significant vertical gain (roughly..

Rubey Rescue Run is a 5K uphill trail race held in Aspen, Colorado. The course climbs Buttermilk Mountain, starting near the base at Buttermilk Mountain Lodge and gaining about 1,700 feet to the Cliff House, offering a timed competition and sweeping views of the Maroon Bells. Participants may run wi..

Boulder XC Series Meet 1 is a family-friendly cross-country event held at Valmont City Park (South) in Boulder, Colorado (5110 Valmont Rd). The meet offers three distances: 1K for younger runners, 3K for those up to 16, and a 5K open race, welcoming participants of all ages and abilities. It’s the f..

Indian Creek Trail Runs, the oldest official race in the Human Potential Running Series, is held at Indian Creek Campground in Sedalia, Colorado. The 12th annual Fall Classic offers four distances — 5-Mile, 15-Mile, 55k, and 50-Mile — with a combined cap of 225 runners. Runners traverse seldom-used..

The Great Trailhead Foot Race 5 & 10 Miler is a trail-running event held at Bear Creek Lake Park in Lakewood, Colorado. Runners choose a 5-mile course or a 10-mile option (two laps) on single-track and dirt trails, with the start/finish at the Pelican Point picnic shelter. Registration includes park..

Beware The Bear Trail Races take place at Bear Creek Lake Park in Lakewood, Colorado. Organizers offer four options: a 5K, a 15K, a 5K+15K Double, and a Kids 1K. The mostly dirt courses feature single and double-track trails with short, steep climbs, rollers, and mixed terrain designed as a friendly..

The Colleen De Reuck XC Classic is a cross country running event held annually at Harlow Platts Community Park in Boulder, Colorado. Honoring renowned distance runner Colleen De Reuck, the race promotes health, fitness, and celebrates local Olympians, with 2025 honoring 2012 Olympic marathoner Yoshi..

The HRCA Backcountry Wilderness Half Marathon is an annual 13.1-mile trail race held in Highlands Ranch, Colorado, featuring a scenic single-loop course through the Douglas County East/West trail and the Backcountry Wilderness Area. The race offers a challenging route on dirt, gravel, and singletrac..

Louisville Trail Race in Louisville, Colorado returns for its 12th year, offering a Half Marathon, 10K, and 5K on scenic trails around Louisville and the Flat Irons. The mostly dirt courses pair gentle elevation with two longer climbs on the half, plus a shorter hill in the 10K and 5K, all out-and-b..

Thumbs Up Vertical Challenge takes place in Estes Park, Colorado, on December 6, 2025. The race uses the Thumb Open Space trail, a 2km out-and-back course with 540 feet of vertical gain per lap. The route is 100% single-track with switchbacks, steps and steep rocks, offering views of Longs Peak, Mou..

Located at Staunton State Park in Pine, Colorado, Sawmill Trail Runs offers three distances: 50k, 16-mile, and 8-mile. The event, now in its 8th edition, starts and finishes at the Ranch Hand Group Picnic Area. With a capped field of 250, the race combines scenic, challenging terrain across Colorado..