Races in CO, United States
73 upcoming races in CO, United States.
73 races found
Ouray 100 Mile Endurance Run
Ouray 100 Mile Endurance Run is a 161 km ultramarathon trail race held in Ouray, CO. The event takes place in July 2026.
High Lonesome 100
The High Lonesome 100 is a high flying endurance race in the Sawatch range of the Colorado Rocky Mountains. With 23,500' of vertical gain and reaching an elevation of 13,100', it's a hell of a course.
Thumbs Up Summer Slam
Thumbs Up Summer Slam is a trail race held in Estes Park, CO. The event takes place in July 2026.
Silverton Alpine Runs
Silverton Alpine Runs is a 50 km ultra trail race held in Silverton, CO. The event takes place in July 2026.
Audi Power of Four Trail Run
The Audi Power of Four Trail Run offers runners a scenic mix of trails across the mountains of Aspen Snowmass. Registrants can choose between the 3 distances offered including 50K, 25K & 10K.
TransRockies Run - Pass to Pub
TransRockies Run - Pass to Pub is a half marathon trail race held in Leadville, CO. The event takes place in July 2026.
Kendall Mountain Run
Kendall Mountain Run is a 11 km trail race held in Silverton, CO. The event takes place in July 2026.
Never Summer 100km & 60km
The Never Summer 100km, 60km and Dirty Double 100 miler will take place almost entirely within the boundaries of State Forest State Park and run between the Never Summer Mountains on the northern. The first 20 miles of each race will offer a tour of the peaks and alpine lakes of the northern Never Summer Mountains, before the route crosses below Cameron Pass and heads north into the southern.
Pikes Peak Ultra
Pikes Peak Ultra is a 50 km ultra trail race held in Colorado Springs, CO. The event takes place in July 2026.
Creede 50/100
Creede 50/100 is a 161 km ultramarathon trail race held in Creede, CO. The event takes place in July 2026.
Box Canyon Trail Races
Box Canyon Trail Races is a 30 km trail race held in Telluride, CO. The event takes place in July 2026.
Grand Mesa Ultras
Grand Mesa Ultras is a 55 km ultra trail race held in Grand Mesa, CO. The event takes place in July 2026.
World Championship Pack Burro Race
The first year of the World Championship Pack Burro Race in 1949 saw 21 entrants with only 8 finishing the race. These days there are nearly 100 racers and burros that take on this historic challenge.
The Summit 200
The Summit 200 is a trail race held in Frisco, CO. The event takes place in July 2026.
Kennebec Mountain Run
Kennebec Mountain Run is a trail race held in Hesperus, CO. Test your alpine running skills on this rugged course that features 3,100 feet of elevation gain, topping out at 12,200 feet through Kennebec Pass.
Winter Park 50K
Winter Park 50K is a 50 km ultra trail race held in Winter Park, CO. The event takes place in August 2026.
Aspen Backcountry
Aspen Backcountry is a 50 km ultra trail race held in Aspen, CO. The event takes place in August 2026.
Sheep Mountain Trail Runs
The Human Potential Running Series Presents: The Sheep Mountain Trail Runs @ Fairplay, CO Come ready my friends, this mountain throws everything it has at trail and ultra runners alike, challenging. You’ll run amongst these “beautifully difficult” mountains and hills lining the western slope of the South Park Valley.
Spartan Race Trifecta Weekend
Spartan Race Trifecta Weekend is a 45 km obstacle race held in Breckenridge, Colorado.
Eltuck Valley 5K - Lory Summer Trail Series
Eltuck Valley 5K - Lory Summer Trail Series is a 5K trail race held in Fort Collins, CO. Our goal is to offer a fun, low-key series of races designed to give newer trail runners an opportunity to dip their toes into the trail racing waters, and to offer more experienced trail racers a.
High Five 100
High Five 100 is a 161 km ultramarathon trail race held in Lake City, CO. The event takes place in August 2026.
Dirt Circus - Boulder
Dirt Circus - Boulder is a trail race held in Boulder, CO. The event takes place in August 2026.
Into the Hills Eltuck 10k
Into the Hills Eltuck 10k is a 10K trail race held in Bellvue, CO. Our goal is to offer a fun, low-key series of races designed to give newer trail runners an opportunity to dip their toes into the trail racing waters, and to offer more experienced trail racers a.
San Juan Softie 100
San Juan Softie 100 is a 161 km ultramarathon trail race held in Durango, CO. The event takes place in August 2026.
Westminster Trail Races
Westminster Trail Races is a 50 km ultra trail race held in Westminster, CO. The event takes place in August 2026.
The Cheyenne Mountain Run
The Cheyenne Mountain Run features three scenic trail races inside Cheyenne Mountain State Park: 25K Mountain Challenge – for advanced trail runners 10K Trail Race – for experienced runners 5K.
Roxborough Ultras
Roxborough Ultras is a 50 km ultra trail race held in Littleton, CO. The event takes place in August 2026.
MOCO Trails Wild West Backyard Ultra
MOCO Trails Wild West Backyard Ultra is a ultra trail race held in Craig, CO. The event takes place in August 2026.
Leadville Trail 100 Run
100 miles at altitude in the Colorado Rockies.
Into the Hills Eltuck 5k
Into the Hills Eltuck 5k is a 5K trail race held in Bellvue, CO. Our goal is to offer a fun, low-key series of races designed to give newer trail runners an opportunity to dip their toes into the trail racing waters, and to offer more experienced trail racers a.
Telluride Mountain Run
Telluride Mountain Run is a 39 km trail race held in Telluride, CO. The event takes place in August 2026.
Eltuck Valley 12K - Lory Summer Trail Series
Eltuck Valley 12K - Lory Summer Trail Series is a trail race held in Bellvue, CO. This fourth race of the series will take place on the fast and flat Valley Trail at Lory State Park.
Ouray 50 Mile Endurance Run
Ouray 50 Mile Endurance Run is a 81 km ultra trail race held in Ouray, CO. The event takes place in August 2026.
Continental Divide Trail Run
5 Mile, 16 Mile and 50K trail races in Steamboat Springs, Colorado.
Rock Hawk
Rock Hawk is a 50 km ultra trail race held in Castle Rock, CO. The event takes place in August 2026.
Front Range Ultra Dayze
Front Range Ultra Dayze is a ultra trail race held in Loveland, CO. The event takes place in September 2026.
Creede Mountain Run
Creede Mountain Run is a 50 km ultra trail race held in Creede, CO. The event takes place in September 2026.
Cirque Series - Arapahoe Basin, CO
Cirque Series - Arapahoe Basin, CO is a trail race held in Keystone, CO. 9.4 miles featuring 2,211' ft vert.
American Heroes Run
American Heroes Run is a 161 km ultramarathon trail race held in Longmont, CO. The event takes place in September 2026.
Trail Sisters Women's Half Marathon & 10k
A Half Marathon and 10K that twist and turn through sage brush and ponderosa pines, all while providing stunning views of the prestige Collegiate Peaks. Located in the Rocky Mountains along the roaring Arkansas River.
53rd Annual Imogene Pass Run
REGISTRATION OPENS JUNE 1 at 6AM MDT The 53rd Annual Imogene Pass Run scheduled for Saturday September 12, 2026. Registration will open on June 1st at 6am MDT, 1550 entries will be offered and we expect to sell out quickly.
Snow Mountain Ranch
Snow Mountain Ranch is a 50 km ultra trail race held in Granby, CO. The event takes place in September 2026.
Devil on the Divide
Devil on the Divide is a 50 km ultra trail race held in Empire, CO. The event takes place in September 2026.
Run Rabbit Run
Run Rabbit Run is a 161 km ultramarathon trail race held in Steamboat Springs, CO. The event takes place in September 2026.
Ouray Mountain Trail Run
Ouray Mountain Trail Run is a trail race held in Ouray, CO. The event takes place in September 2026.
Break of Dawn North Table Trail Race
Break of Dawn North Table Trail Race is a 16 km trail race held in Golden, CO. The event takes place in September 2026.
CG Adventure Club - Elevation Everest
CG Adventure Trip – Mountain Experience This event is a guided CG adventure weekend designed to combine structured training, accountability, community, and an elevated mountain experience. Participants can choose from three registration options based on how much support, logistics, and included amenities they prefer.
Red Feather Trail Jamboree
Red Feather Trail Jamboree is a trail race held in Red Feather Lakes, CO. Come enjoy the clean air and wild spaces of the Red Feather Lakes region in Northern Colorado.
24 Hours of Palmer Lake
24 Hours of Palmer Lake is a trail race held in Palmer Lake, CO. The event takes place in September 2026.
West Line Winder
With glorious views of the Collegiate Peaks and 4,000ft of ascent along the way, these 18 or 30 miles of buttery single track and forest roads are perfect for everyone from the first time trail. Although the Arkansas Valley is famously known for its high alpine peaks, it’s a well kept secret that there’s a stash of arid, desert style trails just outside of Buena Vista (BEW-na Vista), CO -.
Sangre de Cristo Trail Festival
The Human Potential Running Series Presents The Sangre de Cristo Trail Festival @ Music Meadows Ranch Come join us on the Rainbow Trail in the Sangre de Cristo mountains. Run beneath the watchful eye of gorgeous, jagged, and ominous peaks from the confines of the rolling Rainbow Trail.
WILD Wahatoya Runs
WILD Wahatoya Runs is a 50 km ultra trail race held in La Veta, CO. The event takes place in September 2026.
Deep Creek Trail Half Marathon
Deep Creek Trail Half Marathon is a marathon trail race held in Telluride, CO. The event takes place in September 2026.
Crested Butte Ultra
Crested Butte Ultra is a 55 km ultra trail race held in Crested Butte, CO. The event takes place in September 2026.
Estes Epic
Join us for the Estes Epic on September 26-27, 2026 —a premier event featuring a 50k Bike Race, 50k Run, and Heavy Half Marathon. After a six-year hiatus, this challenging race returns, offering participants rugged trails, significant climbs, and breathtaking views of Rocky Mountain National Park.
Sawatch Ascent
A classic, high-alpine, vert-heavy Colorado 50k. Get some miles on the Colorado Trail and run all the way to 13,150' feet in elevation.
Sage Burner Trail Race
Sage Burner Trail Race is a 50 km ultra trail race held in Gunnison, CO. The event takes place in October 2026.
HRCA Wildcat Mountain Trail Races
The Wildcat Mountain Trail Races showcase some of the most scenic terrain in the HRCA Backcountry Wilderness Area, giving runners a true taste of the rolling hills, open views, and natural beauty. Each fall, participants take on two distances—a 10-mile and a 10K—designed to highlight the area’s unique, beautiful trails.
Grand Valley Backyard
Grand Valley Backyard is a trail race held in Loma, CO. The event takes place in October 2026.
Above the Clouds Ultra
Above the Clouds Ultra is a 50 km ultra trail race held in Woodland Park, CO. The event takes place in October 2026.
The Bear Chase
The Bear Chase is a 100 km ultramarathon trail race held in Lakewood, CO. The event takes place in October 2026.
Rubey Rescue Run
Rubey Rescue Run is a trail race held in Aspen, CO. This is a timed race with cash prizes for top 3 female and male finishers.
Indian Creek Trail Runs
The Human Potential Running Series Presents The Indian Creek Trail Runs @ Indian Creek Campground The Indian Creek Trail Runs is the oldest official race of HPRS and is also known as our annual “Fall . Participants will travel through the lower and upper montane ecosystems of the Front Range; from the lodgepole pine forest around 6,000-8,000′ sprinkled with sprawling aspen groves, down to the.
Bobcat Trail Races
Bobcat Trail Races is a 50 km ultra trail race held in Colorado Springs, CO. The event takes place in October 2026.
Blue Sky Trail Marathon & Half Marathon
Blue Sky Trail Marathon & Half Marathon is a half marathon trail race held in Fort Collins, CO. Taking place on the trails between Horsetooth Mountain Park and the Devil's Backbone Open Space, the course takes you on a north-south tour of the easternmost hogbacks of Northern Colorado's mighty.
Bridge Burner Ultra
Bridge Burner Ultra is a 50 km ultra trail race held in Canon City, CO. The event takes place in October 2026.
Kessel Run Ultra
Kessel Run Ultra is a 50 km ultra trail race held in Fruita, CO. The event takes place in November 2026.
HRCA Backcountry Wilderness Half Marathon
The 18th Annual Backcountry Wilderness Half Marathon returns to Highlands Ranch on Saturday, November 7, 2026, at 9:00 a.m. This 13.1-mile race winds through the Douglas County East/West Trail and the scenic Highlands Ranch Backcountry Wilderness Area—offering singletrack, hills, and breathtaking views at every turn.
Marathon At The MAC
Marathon At The MAC is a 5.0 km trail race held in Castle Rock, CO. The event takes place in November 2026.
Louisville Trail Race
Louisville Trail Race is a 10 km trail race held in Louisville, CO. The event takes place in November 2026.
Colorado Cold Rush Ultra
Colorado Cold Rush Ultra is a 50 km ultra trail race held in Colorado Springs, CO. The event takes place in November 2026.
Sawmill Trail Runs
The Human Potential Running Series Presents: The Sawmill Trail Runs @ Staunton State Park The Sawmill Trail Runs; first started as a “Fat Ass” event at White Ranch Open Space in Golden, CO in. We incorporated it into an official trail race starting in December 2017.
Sky Pilots Club Membership
Sky Pilots Club Membership is a trail race held in Ouray, CO. The event takes place in December 2026.