Vail Hill Climb
Course HighlightsThe 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 Mid-Vail at 10,254 feet — a relentless 2,128-foot climb. The route follows the same gravel and dirt service road that has been used since the race was founded in 1976, with 80% dirt/gravel and 20% paved sections. Runners work through dense spruce-fir
Aspen Backcountry Marathon
Course HighlightsThe 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 almost exclusively on single-track dirt trails with diverse terrain: challenging climbs through aspen groves, high ridge traverses with panoramic views of the Elk Mountains, and technical descents back into the valley. The 50K distance includes an out-and-back to the McNamara Hut, part
Imogene Pass Run
Course HighlightsThe Imogene Pass Run is the crown jewel of Colorado's San Juan mountain races. The 17.1-mile point-to-point course climbs from Ouray (7,792 feet) up a historic mining road to the summit of Imogene Pass at 13,114 feet — gaining over 5,300 feet — before plunging 4,800 feet down the other side to finish in the gorgeous mountain town of Telluride. The route passes abandoned mine shafts, crosses alpine tundra covered in late-season wildflowers, and rewards runners with panoramic views
Leadville Trail 100 Run
Course HighlightsThe Leadville Trail 100 Run — the Race Across the Sky — is the defining event of American ultrarunning. The 99.7-mile out-and-back course starts and finishes in Leadville, Colorado (10,152 feet, the highest incorporated city in the United States) and crosses the legendary Hope Pass twice at 12,500–12,600 feet, climbs the rugged Powerline section, traverses technical stretches of the Colorado Trail, and descends to the lowest point of 9,200 feet at Twin Lakes. The course accumulates 15,492 feet of
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
Georgetown to Idaho Springs Half Marathon
Course HighlightsThe Georgetown to Idaho Springs Half Marathon — affectionately known as the GTIS Half — has been a Colorado running institution for nearly five decades. The point-to-point course follows the historic path of the Argentine Central Railroad through the stunning Clear Creek Canyon, connecting the Victorian mountain town of Georgetown to the gold-rush heritage town of Idaho Springs. The route follows the canyon's gentle contours along Clear Creek, offering dramatic rock wall scenery, rushing whitewater, and views of Colorado's
Slacker Half Marathon
Course HighlightsThe 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, losing nearly 2,200 feet over 13.1 miles. The course is a thrilling mix of dirt and paved roads, guiding participants through pristine alpine wetlands and wildflower meadows, past natural waterfalls, dramatic views of the Continental Divide, and through remnants of Colorado's historic
Cherry Creek Sneak
Course HighlightsThe Cherry Creek Sneak is one of Denver's oldest and most beloved springtime running traditions, held annually the last Sunday of April in the vibrant Cherry Creek North neighborhood. Courses of five distances wind through the tree-lined streets of one of Denver's most walkable and stylish districts, passing boutique shops, art galleries, and restaurants. The signature 10-Mile course is the centerpiece for competitive runners, while the 5-Mile, 5K, and 1.5-Mile Sprint options welcome everyone from speedy elites to families
BolderBOULDER 10K
Course HighlightsThe BolderBOULDER is more than a race — it's Boulder's biggest party of the year, drawing over 50,000 participants through the heart of the city on Memorial Day. The 10K course winds through Boulder's eclectic neighborhoods, past live bands, costumed cheerleaders, and lawn-side water stations manned by local characters, before culminating in the stadium finish at CU Boulder's Folsom Field. Runners enter the field to the roar of tens of thousands of spectators and then watch a world-class professional