Pikes Peak Marathon & Ascent
Course HighlightsThe Pikes Peak Marathon and Ascent represent the gold standard of American mountain running. The Ascent covers 13.32 miles from downtown Manitou Springs (6,286 feet) to the 14,115-foot summit of Pikes Peak — America's most famous fourteener — gaining 7,867 feet in a single unrelenting climb over Barr Trail. The full Marathon adds the return trip, demanding runners descend the same brutal trail for a round-trip of 26.2 miles and 7,834 feet of gain and loss. The course passes
Colfax Marathon Relay
Course HighlightsThe Colfax Marathon Relay lets teams of five runners share the full 26.2-mile Colfax Marathon course through Denver's most iconic landmarks. The relay is divided into four legs, sending runners through Empower Field at Mile High on the warning track, along the bustling Colfax Avenue past the State Capitol and VooDoo Donuts, through a full mile inside Denver Zoo with live animal spectators, around Sloan's Lake with Rocky Mountain views, and through Lakewood before returning to the City Park
Colorado Marathon Relay
Course HighlightsThe Colorado Marathon Relay gives teams of runners the chance to tackle Colorado's most scenic downhill marathon course together. Relay teams are divided across the dramatic point-to-point course that descends from the Rocky Mountain foothills through the Cache la Poudre River Canyon — a designated Wild and Scenic River — all the way to the finish line in Washington Park in Old Town Fort Collins. The canyon section features rushing whitewater rapids, dramatic sandstone walls, and cottonwood groves; the
Aspen Backcountry Marathon (Awaiting 2027 Race Date)
⚠️ Estimated date — the 2027 date has not yet been announced by the organizer. We've kept this event visible on the calendar around its usual weekend so you can plan ahead. Please check the official race website (linked below) before booking travel. Course Highlights The Aspen Backcountry Marathon is one of Colorado’s most stunning trail races, utilizing the world-class trail network that surrounds the legendary resort town of Aspen. All three distances — the 50K, marathon, and heavy half-marathon — run
Vail Hill Climb (Awaiting 2027 Race Date)
⚠️ Estimated date — the 2027 date has not yet been announced by the organizer. We've kept this event visible on the calendar around its usual weekend so you can plan ahead. Please check the official race website (linked below) before booking travel. Course Highlights The Vail HillClimb is one of Colorado’s most storied mountain running traditions, celebrating its 50th anniversary in 2026. The 12.2K (7.6-mile) course is a pure uphill race from the base of Vail Village at 8,160 feet to
Slacker Half Marathon (Awaiting 2027 Race Date)
⚠️ Estimated date — the 2027 date has not yet been announced by the organizer. We've kept this event visible on the calendar around its usual weekend so you can plan ahead. Please check the official race website (linked below) before booking travel. Course Highlights The Slacker Half Marathon earns its name — runners start at the base of Loveland Ski Area at a breathtaking 10,630 feet elevation and ride a net-downhill course all the way to Georgetown at approximately 8,400 feet,
Quad Rock 50 & 25 Mile
Course HighlightsThe Quad Rock 50 and 25 mile trail races take place entirely on the premium singletrack trails of Lory State Park and Horsetooth Mountain Park, just west of Fort Collins in the northeastern Colorado Rockies. The 25-mile course features three major climbs and descents totaling over 5,500 feet of vertical gain on 85% singletrack and 15% dirt road, running clockwise from Soldier Canyon. The 50-mile course runs the 25-mile loop twice in opposite directions, accumulating over 11,000 feet of
Horsetooth Half Marathon
Course HighlightsThe Horsetooth Half Marathon is one of the most respected and competitive half marathons in the Mountain West, drawing elite runners and serious age-groupers to the foothills west of Fort Collins each spring. The point-to-point course starts on Dixon Canyon Road in the hills above Horsetooth Reservoir at approximately 6,000 feet, descends through dramatic red rock canyon scenery with views of the reservoir, and finishes at the iconic New Belgium Brewing Company in Fort Collins. The course features +917
HRCA Backcountry Wilderness Half Marathon
Course HighlightsThe HRCA Backcountry Wilderness Half Marathon is one of the Denver metro area's most popular trail half marathons, set within the stunning Highlands Ranch Backcountry Wilderness Area in Douglas County. The 13.1-mile course winds through the Douglas County East/West Trail and the wilderness backcountry on a mix of singletrack, rolling hills, and open-sky ridgelines with breathtaking panoramic views of the Front Range. The trails traverse native grasslands, ponderosa pine forests, and open meadows that are home to deer, foxes,
Crested Butte Ultra
Course HighlightsThe Crested Butte Ultra is a showcase of the extraordinary terrain surrounding one of Colorado's most beloved mountain towns. Three distances — 35K, 55K, and 50 Mile — traverse the Gunnison National Forest on lollipop-loop courses that combine wide-open mountain meadows blanketed with wildflowers at lower elevations, heart-pumping climbs to dramatic mountain ridgelines, and single-track trails through aspen groves that glow gold in late September. The course elevation ranges from approximately 7,500 to 12,500 feet across the 50-mile distance,