Event details subject to change. Please confirm all information via event website.

  • Canceled Ouray 100

    Fellin Park 1001 US-550, Ouray, CO, United States

    With ~42k feet of gain for the 100 miler, this will be one of the most difficult things you ever attempt. Lucky for you, Ouray (dubbed the "Switzerland of America") is also one of the most beautiful places in the world. Situated in the rugged and stunning San Juan Mountain range in southwest Colorado, your […]

  • Audi Power of Four Trail Race

    Aspen Mountain 601 East Dean Street, Aspen, CO, United States

    The Audi Power of Four Race Series is a premier endurance race series utilizing the unique and amazing terrain of each of the four Aspen Snowmass mountains. Each race is designed to test the limits and skills of both elite and recreational athletes. The event’s signature race is a challenging 50K Ultra is part of […]

  • Summer Splash Prairie Dog Half Marathon

    Prairie Dog Race Series
    Castle View High School 5254 N. Meadows Dr., Castle Rock, CO, United States

    Welcome to the Summer Splash Prairie Dog Half, 10k & 5k in Castle Rock, Colorado. Part of the Prairie Dog Half race series, join us in July as we race through Castle Rock along the East Plum Creek Trail.

  • Silverton Alpine Marathon

    Memorial Park - Silverton 1800 Greene St, Silverton, CO, United States

    Experience the best of the San Juan Mountains with an 8 miler, a marathon, or a 50 kilometer run along the Alpine Loop past the historic mining ghost towns of Howardsville, Eureka, Animas Forks & Gladstone. High point is 12,930 ft atop California Pass. Low point is Silverton at 9,318ft. Total vertical gain is 3,800 […]

  • Kids’ TRY-athlon

    H2O'Brien Pool 10795 Victorian Dr, Parker, CO, United States

    This event is all about fun over competition. Boys and girls of all ability levels show their skills in three events: swimming, biking and running. Come on, kids, TRY it out!  Ages: 6 to 12, based on event date Event Distances 6-7 years: 25m swim (1 length)/ 0.75 mile bike/ .5 mile run 8-10 years: 50m […]

  • Mountain Swim Series II

    Carter Lake 971 N County Rd 31, Berthoud, CO, United States

    The crossing is at Carter Lake, Colorado. Situated at just below 5800 feet, this nearly 3-mile swim is located in one of the most picturesque lakes in Colorado. Cash prize awards will be given out to the top three finishers in each division.  Divisions will be both non-wetsuit and wetsuit for both men and women. […]

  • 719 Challenge 10K

    Goose Gossege Park 3950 Mark Dabling Blvd, Colorado Springs, CO, United States

    The 719 Challenge run will be the official 10-kilometer (6.2 mile) run of the Rocky Mountain State Games, and, a medal event. The course will feature a mix of road and crushed gravel trails on a mostly flat, relatively fast course.

  • Tri Boulder

    Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

    ‘The Beast’ Long Course distance will be back for its second year! As one of Colorado’s most popular summer triathlons, Tri Boulder offers many different multisport race distances, all in one eventful day. Take in the natural beauty of the mountain backdrop that sets the scene for this iconic race destination. Most of the bike […]

  • Thumbs Up Summer Slam

    Thumb Open Space 101 Peak View Drive, Estes Park, CO, United States

    Repeating 2km out-and-back laps on the Thumb Open Space trail, 540ft of vertical gain each. Start at 7:10am, finish at 7:10pm. Sunup to sundown. Collect a poker chip at the turnaround on each lap. Most chips wins. Distance awards at three milestones: 14 ascents — Estes Park 7,522' 18 ascents — Deer Mountain 10,103' 26 […]

  • Toni’s Trot 5K

    La Salle Community Center 101 Todd Ave, La Salle, CO, United States

    The Town of LaSalle will host the 36th annual Toni’s Trot. This event kicks off a full day of celebration this community knows as “LaSalle Days”. Proceeds from the run will benefit the Recreation Department operating programs for all ages in LaSalle and surrounding communities.

  • Please click here to submit your event for FREE to our online calendar.
    We do not allow events without physical locations (IE – virtual runs, runs with locations TBD, etc…).
    Please allow 48 hours after submission for an event to appear on the calendar. If you have already listed your event and would like us to update it, please contact us.