Here in Colorado, we have high altitude, pristine alpine lakes, a plethora of amazing trails, and an entertaining number of 14ers.(Just ask Kilian Jornet!). All of that stunning geography means we also have lots of great trail running races! (Including the Devil on the Divide 50K pictured above.) The following is a partial list of races that has put the state on the map as one of the premiere trail racing destinations. This is a nowhere-near-exhaustive list of the amazing races that Colorado has to offer, but it has a range of long, rugged, and scenic ultras to short and blazingly fast singletrack events.
In addition to the events featured below, also check out the Royal Gorge Groove (April 25, Canon City), Falcon 50 (April 25, Colorado Springs), Cheyenne Mountain Trail Races (April 25, Colorado Springs), Take 5 in the Garden (May 2, Colorado Springs), Sky Pilots Backyard Ultra (May 16, Ouray), Ram Party (May 16, Colorado Springs), Durango Trails Backyard Ultra (May 30, Durango), Ring the Springs (June 20), Grand Mesa Ultras (July 25, Grand Mesa), San Juan Softie 100 (Aug. 14, Durango), Ouray 50 Mile Endurance Run (Aug. 29, Ouray), The Sneffles Round (Aug. 30, Ouray), Ouray Mountain Trail Run (Sept. 19, Ouray), Above the Clouds Ultra (Oct. 3, Woodland Park), and the Louisville Trail Races (Nov. 14, Louisville).
Which ones are you putting on your 2026 race calendar?
Looking for races in another state or region? Visit UltraSignup’s race finder.
And make sure you put the August 8 Boulder stop of the Dirt Circus tour on your calendar, too!
RELATED: 15 California Trail Races You Need to Run
Valkyrie Trail Race
May 9, Colorado Springs
50K, 26.2 miles, 30K, 13.1 miles, 8 miles, 4 miles
The Valkyrie Trail Race is a women-centered trail running event at Cheyenne Mountain State Park, offering distances from 4 miles to 50K in a welcoming, community-driven setting. The courses start across open meadows on smooth crushed limestone paths before winding onto singletrack that climbs gradually toward the ridges of Cheyenne Mountain.
From there, runners drop into pine-covered canyons and navigate stretches of rockier, more technical trail, creating a varied mix of fast, runnable terrain and more demanding sections. With rolling elevation changes, diverse landscapes, and sweeping views of the foothills and city below, the race provides a balanced trail experience that’s both accessible and engaging.
Organized by Mad Moose Events
More Details and Registration: Valkyrie Trail Race
The Great Divide Ultra
June 6-7, Divide, Colorado
100 miles, 100K, 50K Sat, 50K Night, 50K Sun, 25K Sun, 25K Night, 25K Sat
If you are into mountainous beauty but don’t want the technical terrain, The Great Divide Ultra is the race for you! Offering distances from 25K to 100 Miles with numerous start times over the weekend that can fit any busy schedule. Do you work on the weekends? No problem, they have an 8:00pm 25K and 50K start for you.
A full weekend of festivities offers three 25K and three 50K options, along with a 100K and a 100 Mile options. The rolling singletrack and doubletrack trails in Mueller State Park provide epic views of the west side of Pikes Peak. Although the trails are not technical, elevation exceeds 9,000 feet, so make sure you hydrate well. This is easily done with the well-stocked aid stations and convenient access for your crew. Past participants consistently praise the race organization and volunteers for the fun environment, grassroots feel, and natural beauty of the area.
Organized by Revenant Running
More Details and Registration: The Great Divide Ultra
TransRockies Run: Pass to Pub
June 19-21, Leadville, Colorado
Full Pint (51 miles), Half Pint (31 miles)
Last year saw the sunsetting of the three- and six-day TransRockies Run … but don’t fret, organizers are back with a three-day adventure known as Pass to Pub! It is still being dubbed as “Summer Camp for Big Kids!” Beer will definitely be involved.
Two race options are offered over a three day period: Full Pint and Half Pint. The three stages of the Full Pint, totaling 51 miles with 9,635 feet of elevation gain, will take runners up and over the famed Hope Pass (12,600 feet), transverse the Continental Divide near Leadville, and finish in the quaint town of Red Cliff. The Half Pint is the “light” version, covering 31 miles and 6,855 feet of elevation gain.
The intense climbs with epic views of the Rockies are complimented by the communal gatherings at “ChillVille” lounge, live bands, tent camping under the night’s sky, options for catered meals, massages, and athletic therapy. Make new lifelong friends as you suffer then celebrate together. And beer, of course!
Organized by TransRockies Run
More Details and Registration: TransRockies Run: Pass to Pub
San Juan Solstice 50
June 21, Lake City, Colorado
50 miles
Celebrating its 30th year in 2025, San Juan Solstice 50 is one of those old-fashioned, grassroots ultra races that your elder running buddies tell you about. Even more breathtaking than the raw beauty of the San Juan Mountains of Colorado, is the sustained 4,000-foot climbs (topping out at 13,000 feet) that you will have the pleasure of enjoying.
And if you side with the Luddites, you will enjoy this next fact. Unlike modern races, it employs a low-tech approach with volunteer and paper-based tracking. Like any great grassroots event, proceeds benefit the local Lake City volunteer EMTs and other public services. One of the best attributes of SJS50 is that it is held around the June solstice, marking the onset of summer and the longest day of the year!
Organized by Lake City Community
More Details and Registration: San Juan Solstice 50
Hardrock 100 Endurance Run
July 10-12, Silverton, Colorado
102.5 miles
The motto for this one is “Wild & Tough,” and it certainly applies to the course and the runners who complete it. Wild for grand and remote mountains of the San Juans and Tough for…well, probably the chances of getting into the race. All those memes you see on social media about the difficulty of getting in have some truth to them. But don’t let that deter you from entering, it only takes one of your tickets to get drawn and you are in!
Memes aside, Hardrock may be the most beautiful (and challenging) 100 miler out there. With 33,197 feet of elevation gain, and equal amount of loss—that’s 66,394 feet elevation change!—you get as high as Handies Peak (14,048 feet) and only dip as low as 7,680 feet in the town of Ouray, making the average elevation 11,186 feet for the entire course. The course direction alternates each year, requiring runners to “kiss the rock” at the finish in order to stop their time. This small, grassroots-feeling race with immense beauty and community involvement, where race director Dale Garland is waiting to greet every finisher as they cross the line (“kiss the rock”) is everything we love about ultrarunning. Best of luck in the lottery!
Organized by Hardrock Hundred Endurance Run
More Details and Registration: Hardrock 100 Endurance Run
Ouray 100 Mile Endurance Run
July 17, Ouray, Colorado
100 miles
The Ouray 100 is a rugged ultramarathon that is often regarded as one of the most demanding trail races in the U.S. The course covers roughly 102 miles with more than 40,000 feet of vertical gain, taking runners across steep mountain passes, historic mining routes, and remote alpine terrain in the San Juan Mountains.
It’s an exceptionally difficult and remote event that pushes endurance, navigation, and mental resilience, delivering one of the most grueling and scenic mountain running experiences in North America. The course weaves together a challenging mix of narrow singletrack, jeep roads, and high-elevation trails, with sustained climbs and punishing descents frequently above 10,000 feet. Runners face constantly changing conditions, from rocky, technical footing to exposed ridgelines and rugged mining paths, all surrounded by dramatic peaks and deep mountain basins.
More Details and Registration: Ouray 100 Mile Endurance Run
Kendall Mountain Run
July 19, Silverton, Colorado
12 miles, 11K
If you hear about a race that started as a bar bet, you know it’s going to an amazing challenge! As the story goes, in 1908 a miner and a saloon owner in the mining boomtown of Silverton made a wager whether or not the looming Kendall Mountain could be ascended and descended in under one and a half hours. It was not accomplished but news spread, leading to a fatality during an attempt. Flash forward to 1978 when the less dangerous course of 12 miles was implemented.
Starting downtown at 9,318 feet, the race takes the steep and rocky jeep road ascent before the 250-foot scramble to the summit at 13,066 feet, where you can take in the almost 4,000 feet of climbing you just accomplished. Then the fast descent will carry you back to town and finish in the historic Memorial Park. Be warned, your quads will be very sore!
Organized by Aravaipa Running
More Details and Registration: Kendall Mountain Run
Creede 50/100
July 25, Creede, Colorado
100 miles, 50 miles
The Creede 50/100 is a rugged, high-altitude ultramarathon that sends runners on a demanding journey through the remote San Juan Mountains. The race features 50- and 100-mile options that climb above 12,000 feet and traverse long stretches of pristine singletrack, including extended sections along the Continental Divide with sweeping alpine views.
The course blends smooth dirt trails, jeep roads, and rugged alpine terrain, with significant elevation gain topping 20,000 feet and a high point above 13,000 feet. It’s a remote, self-reliant-style ultra that emphasizes adventure over precision, challenging runners with thin air, changing mountain conditions, and a constantly shifting mix of high-country terrain.
Organized by Tempest Adventures
More Details and Registration: Creede 50/100
Grand Mesa Ultras
July 25, Grand Mesa, Colorado
50 miles, 55K, 30K
Started in 2010, this is one of Colorado’s hidden gems. The Grand Mesa Ultras take runners high onto the world’s largest flat-topped mountain for a rugged and scenic high-altitude challenge. Courses wind through alpine forests, past hundreds of lakes, and across rolling mesa terrain, with distances typically including 30K, 50K, and 60K options. The elevation—often above 10,000 feet—adds a demanding physiological edge to an already technical trail experience. Known for its scenic beauty and remote feel, the race offers a true mountain ultra atmosphere despite its relatively runnable terrain.
Organized by Best Slope Events
More Details and Registration: Grand Mesa Ultras
Box Canyon Trail Races
July 25, Telluride, Colorado
30K, 10 miles
The Box Canyon Trail Races in Telluride is a rugged high-alpine event that sends runners on steep loop courses through the dramatic San Juan Mountains, blending sustained climbs with fast, technical descents. The longer 30K climbs from town past stunning Bridal Veil Falls into alpine basins and meadows before topping out around 13,000 feet and dropping back via ridgelines and ski-area trails.
Both race distances feature relentless elevation gain—up to roughly 6,000 feet—and sweeping 360-degree views of jagged peaks, deep box canyons, and high tundra terrain that define this corner of the San Juans. Overall, it’s a quintessential Colorado mountain race: thin air, big vertical, and constantly changing terrain that showcases both the beauty and brutality of running above treeline.
Organized by Confluence Events
More Details and Registration: Box Canyon Trail Races
Pikes Peak Ultra
July 25, Colorado Springs
50 miles, 50K, 30K, 20K
The Pikes Peak Ultra is a midsummer trail running event offering a range of distances set beneath the iconic slopes of Pikes Peak. It’s widely considered one of the more approachable ultras in Colorado, delivering a solid challenge without the extreme technicality or altitude of the state’s toughest races.
The courses roll through foothill and mountain terrain on a mix of dirt and granite-strewn singletrack, with steady climbs and flowing descents. Runners get continuous views of Pikes Peak and the surrounding Front Range while navigating terrain that balances runnable sections with moderate, strength-testing ascents. It’s a scenic and well-rounded event that offers a genuine mountain running experience while remaining accessible to those stepping up to longer distances.
Organized by Mad Moose Events
More Details and Registration: Pikes Peak Ultra
Aspen Backcountry Trail Races
Aug. 1, Aspen, Colorado
50K, 26.2 miles, 13.1 miles
The Aspen Backcountry Trail Races start near this world famous ski town and quickly head into the surrounding Elk Mountains on mostly dirt singletrack and doubletrack trails, featuring sustained ascents, high-altitude sections, and long, flowing descents. Runners encounter a mix of smooth forested trails, rocky alpine stretches, and exposed high-country terrain, often with limited aid and a true backcountry feel.
With elevations climbing well above 10,000 feet and expansive views of rugged peaks and valleys, the races deliver a challenging yet scenic, high-alpine experience that highlights the spectacular singletrack trails surrounding Aspen.
Organized by Aravaipa Running
More Details and Registration: Aspen Backcountry Trail Races
Westminster Trail Races
Aug. 15, Westminster, Colorado
50K, 35K, 13.1 miles, 10K, 5K
The Westminster Trail Races take place in the open space and greenbelt system around Westminster, offering a surprisingly scenic trail experience on the north side of the Denver metro area. The courses wind through gently rolling terrain on a mix of wide dirt paths, crushed gravel, and smooth singletrack, making them approachable for beginners but still engaging for experienced runners. Runners move past prairie grasslands, small lakes, and creekside corridors, with long sightlines and views toward the Front Range. Overall, it’s a fast, non-technical race that emphasizes flowy terrain and consistent pacing rather than steep climbs or rugged mountain challenges.
Organized by Aravaipa Running
Info and Registration: Westminster Trail Races
RELATED: Behind the Bib: Louisville (Colorado) Trail Races
Telluride Mountain Run
Aug. 22-23, Telluride, Colorado
Hill Climb, 65 miles, 40 miles, 24 miles, 14 miles
The Telluride Mountain Run is a notoriously tough high-alpine race set deep in the San Juan Mountains above Telluride. It offers a range of events—including a vertical hill climb, 14-mile, 24-mile, 40-mile, and a demanding 65-mile race—all built around steep ascents and highly technical terrain.
Perched above a historic box canyon and surrounded by jagged peaks, the race delivers constant exposure to altitude, dramatic scenery, and rapidly changing mountain weather. The courses wind across old mining roads, narrow singletrack, alpine tundra, and exposed ridgelines, often climbing above 13,000 feet on rocky, loose, and sometimes faint trails. More than a traditional race, it’s a true mountain running test, known for its difficulty, adventurous routes, and gritty, no-frills atmosphere that draws experienced runners seeking a serious alpine challenge.
Organized by Telluride Mountain Run
More Details and Registration: Telluride Mountain Run
Continental Divide Trail Run
Aug. 29, Steamboat Springs, Colorado
50K, 16 miles, 5 miles
The Continental Divide Trail Run a classic demanding-yet-scenic Colorado trail running event that start and finish near the base of the Steamboat Ski Area. The courses climb quickly through aspen groves and pine forests, with much of the elevation gain concentrated early before reaching high points above 10,000 feet along the Continental Divide.
Runners traverse a mix of smooth dirt paths, flowing forest singletrack, and moderately technical sections with rocks and roots, all framed by expansive views of the Yampa Valley. Longer distances venture farther into alpine terrain, including climbs toward Mount Werner and out to scenic high-country areas like Long Lake, with total elevation gain approaching 5,500 feet.
Organized by the Steamboat Running Series
More Details and Registration: Continental Divide Trail Run
Devil on the Divide
Sept. 6, Empire, Colorado
50K, 22K
This devil of a race will start high and take you higher. There is a understandable reason as to why this race requires participants of the 50K to have past ultra running experience. Runners climb over 6,500 feet of elevation and reach the highest altitude of 13,200 feet in the 50K. Keep in mind that 80 percent of race is run above 10,000 feet. And don’t think the 22K is going to give you a break, it gains 3,400 feet of elevation over its distance.
Don’t let those stats scare you off, these point-to-point races offer a majority of singletrack and offer a good mix of runnable and moderately technical trails. The wispy, high altitude trails will quench your thirst for beautiful scenery. And like all small, local races, this one is filled with good ol’ grassroots vibes.
Organized by The Clear Creek Metropolitan Recreation District
More Details and Registration: Devil on the Divide
Run Rabbit Run
Sept. 18-19, Steamboat Springs, Colorado
100 miles, 50 miles
This cute, fuzzy animal-themed race takes place in Steamboat Springs and runs through the beautiful Routt National Forest of northern Colorado. But don’t be fooled, it is still a beast with ~9,000 and ~22,000 feet of ascent in the 50 mile and 100 mile, respectively. The unique “Hares vs. Tortoises” race format allows those runners who want a more generous finish time (36 hours) to start four hours ahead and utilize pacers to run the Tortoise category. The more competitive Hare category gets a 30-hour race limit, no use of pacers, but does get the opportunity to chase the Tortoises down and compete for the enormous $100,000 prize purse, with first place male and first place female receiving $20,000 for the win.
This race is encouraging for both the competitive athlete and a first-time 100-mile runner who wants to experience a beautiful environment but wants a little more time to do so. Your entry will also make you feel altruistic, as it is a charity race and has already donated almost $700,000 to great causes like benefitting Colorado kids! So if this sounds like your vibe, hop on over and sign up for Run Rabbit Run.
Organized by Run Rabbit Run
More Details and Registration: Run Rabbit Run
RELATED: Run Rabbit Run: A Steamboat Classic with Heart, Competition, and $100,000 on the Line
Crested Butte Ultra
Sept. 26, Crested Butte, Colorado
50 miles, 55K, 35K
Crested Butte is known for having some of the best mountain bike trails in the country and runners get to experience it all at Crested Butte Ultra! Traversing through the Gunnison National Forest, runners will be amazed at the wide open views! Single track trails take runners through beautiful mountain meadows and up to stunning mountain ridges.
At the lower elevations, stunning wildflowers set against mountain backdrops will greet runners as they work their way up the course. Fall foliage rivaling New England will distract them from the heart pumping climbs. Come enjoy a weekend getaway in this quintessential mountain town.
Organized by Mad Moose Events
More Details and Registration: Crested Butte Ultra
Bridge Burner Ultra
Oct. 24, Canon City, Colorado
35 miles, 50K, 35K, 10K
The Bridge Burner Ultra is a late-season trail race in Cañon City that highlights the rugged landscape surrounding the Royal Gorge and the Arkansas River corridor. It offers a range of distances—from 10K to 50K and a 35-mile option—beginning near Centennial Park before heading onto scenic riverside trails and through the granite tunnels of Tunnel Drive.
From there, runners climb steadily to elevations just above 7,000 feet before transitioning onto miles of smooth, flowing singletrack in Royal Gorge Park, with occasional dirt roads and rocky stretches adding variety. Highlights include crossing the Royal Gorge Bridge and descending through Temple Canyon, blending fast, runnable terrain with moderate elevation gain of roughly 4,500 feet.
Organized by Revenant Running
More Details and Registration: Bridge Burner Ultra
Sage Burner Trail Races
Oct. 3, Gunnison, Colorado
50K, 28K, 15K
The Sage Burner Trail Races take place in the high desert sagebrush country outside Gunnison, offering a stark contrast to Colorado’s alpine races with wide-open vistas and rolling terrain. The courses traverse a network of smooth singletrack and doubletrack through dry, dusty soil, with occasional rocky sections and punchy climbs that keep the rhythm honest. Runners are exposed to sun, wind, and big skies for most of the race, with constant views of surrounding mesas and distant peaks. Overall, it’s a fast but deceptively challenging event where footing is generally runnable, but the undulating terrain and altitude gradually wear you down.
Organized by One Love Endurance Events
More Details and Registration: Sage Burner Trail Races
Bobcat Trail Races
Oct. 17, Colorado Springs, Colorado
50K, 25K, 10K, 5K
The Bobcat Trail Races take place at Palmer Park, offering a mix of accessible distances on one of the city’s most scenic urban trail systems. The courses wind through rolling mesas and sandstone formations on a blend of hard-packed dirt singletrack, wider gravel paths, and short rocky sections that add just enough technical variety. Expect frequent twists and turns, punchy climbs, and quick descents rather than long sustained ascents, making it a rhythm-changing course that keeps runners engaged. With expansive views of Pikes Peak and the Front Range, it delivers a classic Colorado Springs trail experience without venturing far from town.
Organized by Aravaipa Running
More Details and Registration: Bobcat Trail Races
Beware the Bear Trail Races
Oct 25, Lakewood, Colorado
5K+15K Double, 15K, 5K, Kids 1K
Beware the Bear is a classic introduction to trail running for those who interested in jumping onto the dirt! Offering approachable distances of 5K and 15K; or if you are a seasoned trail runner and want to challenge yourself with the 5K-plus-15K double, that is a double threshold option. The kids even get their own spotlight with the Kid’s 1K. And what better motivation for them that the coveted finishers stuffed animal!
The trails in Bear Creek Lake Park in the outskirts of Denver offer almost all dirt courses with varying terrain consisting of flowy singletrack, rocks and roots, punchy climbs, and creek crossings. You are also treated to glorious views of the Rocky Mountains as you run creekside. If you are one who worries about navigations, don’t. All courses will be well marked with a “Won’t-Get-Lost” guarantee. Also, no need to fret about the namesake of the race, the only bears you will see are the fluffy stuffed kind.
Organized by Run Uphill Racing
More Details and Registration: Beware the Bear Trail Races
Kessel Run Ultra
Nov. 8, Fruita, Colorado
10 Mile, 20 Mile, 50K, 40 Mile, 50 Mile
Fruita might be a popular area for world class mountain biking, but it is also features fantastically flowy running trails! The Kessel Run Ultra in eastern Colorado has an approachable distance for everyone. With five distance options, the loop courses are both and flowy and punchy and offer scenic views of the San Juan Mountains and the Colorado National Monument. How fun does the Zippity-Do-Da Trail sound!?
The terrain seems as if it was from a different planet, which is very appropriate since the Kessel Run is a treacherous hyperspace route in the Star Wars universe. The race organization offers camping with access to local amenities like cool cafes and quaint coffee shops. And if you want convenience, how does walking from your camp site to the race start sound? Just beware of the Ewoks!
Organized by Mad Moose Events
More Details and Registration: Kessel Run Ultra
Colorado Cold Rush Ultra
Nov. 21, Colorado Springs, Colorado
50K, 13.1 miles, 10K
The Colorado Cold Rush Ultra is a winter trail race in Colorado Springs that delivers a true cold-weather test on historic mountain routes shaped by the region’s gold rush era. It offers multiple distances—including a 50K, half marathon, and 10K—on mostly out-and-back courses beginning at Bear Creek Regional Park, climbing High Drive, and extending onto Gold Camp Road.
The route is entirely on trails, mixing smooth dirt with occasional rocky, uneven sections, and runners often encounter snow or icy patches depending on conditions. What makes the event stand out is its steady climbing to elevations near 9,000 feet, passage through historic mountain tunnels, and expansive views above the city, all combining for a scenic yet demanding winter running experience.
Organized by Revenant Running
More Details and Registration: Colorado Cold Rush Ultra
Sourdough Snowshoe Race
Mid-January, Nederland, Colorado
18K, 30K
Colorado trails are not only for the summertime! The Sourdough Snowshoe Race is a challenging backcountry event held in the Roosevelt National Forest in the height of winter. The 18K and 30K options are considered a difficult, emphasizing backcountry skills alongside physical endurance. Both distances climb to a high point of 10,000 feet. The rugged terrain of the courses, potential for deep snow, and significant elevation make it demanding so make sure you are prepared with at least 20 ounces of liquid and 600 calories of nutrition.
This is a donation-based event, so pay what you can afford. Come for the challenge of backwoods snowshoe running, but stay for the finish line “hangout” to unwind with hot cider and cocoa.
Organized by Trail Trash Adventures
More Details and Registration: Sourdough Snowshoe Race
About the Author
Peter Maksimow is a Colorado-based trail runner and photographer known for blending endurance sport with visual storytelling. As an trail runner, he has competed in a range of mountain and trail events, representing Team USA several times and helping the U.S. earn the silver medal at the World Long Distance Mountain Running Championships in 2015.
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