Event details subject to change. Please confirm all information via event website.
Dirty Dozen Trail 10K
New Castle Trails’ 2026 Downvalley Dirty Dozen is a reimagining and celebration of trail running, mountain biking, music, and community. The weekend is full of fun including live music from regional bluegrass bands, plus mountain biking and trail running races for all ability levels on the Colorow and Highlands trail networks. Racers can also enter the duathlon […]
Eldorado Springs Run for the Cure
Founded in 1979, the Eldorado Run for the Cure is the longest operating charitable footrace in the State of Colorado. All proceeds from the annual four-mile run benefit the Colorado Cancer Foundation's life-saving work, from funding oncology research at the University of Colorado's (CU) Division of Medical Oncology to aiding patients at the CU Hospital […]
Boulder Stroke & Stride IX
Boulder Reservoir 5565 N 51st St, Boulder, CO, United StatesThe Boulder Stroke & Stride offers Boulder area athletes a fun 1-lap 750 Meter Swim, or 2-Lap 1500 Meter swim in Boulder Reservoir, followed by a 5k run on the reservoir dam. Stroke & Stride happens weekly on Thursday nights throughout the Summer from June 4th to August 6th WITH THE EXCEPTION OF Thursday June […]
BRR Summer Track Series #5
Potts Field 4001 Discovery Drive, Boulder, CO, United StatesJoin the Boulder Road Runners as we host the premier track and field meet series in Colorado! Tradition runs deep with this legacy event. Now in its 4th decade, the meets welcome people of all ages and abilities – youth, masters, elites, and age-groupers alike. Heats are organized by predicted finish time, giving everyone peers to […]
Canceled High Five 100
In 2018 local ultra runners of Lake City came together to create a challenge meant to shake even the most elite runners to their core. What we came up with is the High Five 100. To complete this challenge, you must begin in Lake City and make your way on foot to 24 specified locations, consisting […]
First Fridays 5K
Festival Park 199 Perry St., Castle Rock, CO, United StatesFriday nights in the summer are made for spending time close to home, enjoying the beautiful weather, and unwinding from the long week. Why go anywhere else but Downtown Castle Rock? Start the night off on the right foot with the First Fridays 5K. Before enjoying the free concert event, get a workout with the […]
Ute 100
The Ute 100 is the highest and most scenic race in Utah, taking runners on a breathtaking tour of the La Sal Mountains, Utah's second highest mountain range. The 100 mile course has an average elevation over 8,700 ft and boasts roughly 23,000 ft gain.
Emerald Mountain Epic
The Emerald Mountain Epic presented by Hard Headed attracts some of the nation's best mountain bike and trail running racers, while still offering incredible opportunities for athletes of all skill levels to test their meddle. Our race is a uniquely rewarding and challenging experience in that it is 90% singletrack with major elevation gains. To […]
Reece’s Roundup 5K/10K
Join the Rubino Family at Philip S Miller Park in Castle Rock for the Annual Reece’s Roundup 5K/10K. This event supports Reece Rubino in his fight against Spinal Muscular Atrophy.
All-Out Runapalozza
As those summer mornings are just beginning to cool, join us for a celebration to end the season and our 11th Annual Runapalooza! From the award winning Apex Center, these 5K, 10K & Half Marathon courses will run west along the 2020 Best of the Best Ralston Creek Trail through Arvada's open spaces and stunning golf […]
Georgetown to Idaho Springs Half Marathon
Part of the Colorado Mountain Half + Series, Georgetown to Idaho Springs Half Marathon is a Colorado Runner’s Must-Do. This iconic Half Marathon is one of the most pleasurable races in the western US. The point-to-point course is a scenic and gently rolling downhill mountain course that winds down the Clear Creek Valley -- starting at an […]
Human Race Half Marathon
Civic Center Park - Fort Collins Fort Collins, CO 80521, Fort Collins, CO, United StatesWhat is better than one day of running? TWO days of running! The Choice City Running Event in Civic Center Park Fort Collins has something for everyone. Kick off a run-filled weekend with the Jane Welzel Mountain Avenue Mile on Friday evening with 1-mile races for everyone including kids, middle & high school students, families, […]
Summer Sizzler 5K
Join us for the annual Summer Sizzler! Whether you are looking to run, walk or just enjoy the race SWAG this race is a sure thing for a great time and an incredible experience! This is a fun, family event for all ages with all distances! Great Swag - designer shirt & custom medal Chip-timing […]
Pat’s Pony Express Trail Run
Pat's Pony Express is a trail run at Rampart Reservoir. There are two distance options: 8 miles and 16 miles. Come out and enjoy the single track, running creeks, wildlife, and Colorado's autumn glory. This race is small by design and always will be. The US Forest Service limits the number of participants so the […]
Run the Rockies Trail Half Marathon
The Run the Rockies Trail 5k, 10k, and half marathon will lead runners through the Frisco Peninsula trails with breathtaking views of Dillon Reservoir and the Ten Mile Range. This is a great course for a first time half-marathoner or runners looking for a fun course that offers single track and dirt road trails. Racers […]
Arapahoe Warrior 5K
Come out and support the Arapahoe Warrior Cross Country team at the 3rd annual Arapahoe Warrior 5K. $10.00 of every registration goes directly back to the Arapahoe Cross Country Booster team.
Escalante Days 5K
All proceeds support the Dolores Middle and High School Cross Country programs.
Dog Days of Summer 5K
Come join us on August 8, 2026 for a race around the entirety of beautiful Lake McIntosh! This 3.5 mile race is a half paved/half dirt course surrounded by wonderful mountain views, vast farmlands, and beautiful aquatic wildlife! Gather at Dawson Neighborhood park near the pirate ship playground where you will find an assortment of […]
5K at the Fair
Please join La Plata County 4-H for the inaugural 5K at the Fair! The race will be on August 8 at 8:30 AM at the La Plata County Fairgrounds in Durango, 2500 Main Ave. Check in starts at 8 AM. We will be meeting on the lawn, next to the Extension Building. Runners and walkers […]
Strides For Change
Join us on August 8th, 2025 at Sloan’s Lake for Strides for Change – a 5K for Youth Mental Health, presented by Resolute Counseling Center. This community-centered event is more than a race — it’s a movement to support and uplift the mental health of our youth. Hosted by Resolute Counseling Center, whose mission is to […]
St Vrain for the Brain 5K
Run or walk this charity 5k in which all proceeds benefit brain cancer research! There will be trophies for the top finishers in men, women, and youth. Costumes are encouraged — the best costume wins a prize!
Sarcoma Strong 5K
Hi all! Please join us at Sloan's Lake Park in Denver on 8/8 for a 5K to raise awareness for cancer! Specifically, sarcomas, a group of cancers that affect tissues such as bone and muscle. We hope to raise awareness for these often deadly, debilitating, and often overlooked cancers; for survivors, families, and the research/medical […]
Eat. Run. Adopt. 10K
Join us for Berthoud’s first-ever community-driven 10k! In partnership with Berthoud Pet Supply, this isn’t just a race—it’s a moving feast with a mission. A portion of race registration proceeds will go to Scroungy Dogs and Pretty Pups Rescue This community race and expo is designed to support Scroungy Dogs and Pretty Pups Rescue, a […]
Summer Sizzler 5K
Join us for the annual Summer Sizzler! Whether you are looking to run, walk or just enjoy the race SWAG this race is a sure thing for a great time and an incredible experience! This is a fun, family event for all ages with all distances!
Rocky Mountain Tri-Fest
Rocky Mountain Tri-Fest is Colorado's newest Multisport event, catering to the whole family. With events for everyone from mom and dad looking to try their hand at a gravel triathlon, to children looking to do their first triathlon. The Sprint and Super Sprint gravel Tris are beginner friendly with the bike course on the gravel […]
Bullfrog Summer Surge
The Bullfrog Summer Surge is a community first race morning built around movement, connection, and summer fun. Set at Addenbrooke Park, there's something for every pace: a timed 5K for PR chasers, a relaxed Hot Lap for walkers and joggers, and a Kid's only version of the half mile Hot Lap for tadpoles ready for […]
Berkeley Circuit
Event Description Berkeley Circuit Race Schedule: 8:30- Free and Fun Kids Quarter Mile (no registration necessary, just show up to race!) 8:45- Community One Mile Run (all paces welcome- walkers, strollers, dogs!) 9:15- Competitive Waves Begin (10 person waves from slowest to fastest seed times) *All registered participants will receive a performance race tank with original […]
Summit Trail Running Series V
Carter Park 500 South High Street, Breckenridge, CO, United StatesExplore the trails of Breckenridge this summer with the 23rd annual Summit Trail Running Series with each race followed by a post-race party! The Series consists of 5 trail races in and around Summit County, May-July. Each race features a short and long course, and all races are open to runners of all abilities ages […]
San Juan Softie 100
The softest 100 miler in the San Juans This 100 mile ultra marathon starts and finishes just north of Durango, Colorado. The race will take you through some of the most stunning and rugged terrain with breathtaking views of the Colorado Trail, Engineer Mountain, Wilson group of 14ers, Lizard Head, and many other incredible peaks […]
Weld County Commissioner’s Cup
This is a private event for Weld County employees and their families. The race is not open to the general public. Sorry!
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