Trail Running calendar near Boulder 2024-2025

The Mountain Peacock 50k is an exciting ultra running event taking place in Golden, Colorado, where participants will conquer four peaks in one day. This inaugural event emphasizes a no-frills approach, focusing on the essence of trail running without expensive fees or elaborate aid stations. Runner..

The Sawmill Trail Runs, organized by the Human Potential Running Series, is set to take place at Staunton State Park in Pine, Colorado. This annual event, which began in 2013, features three distance options: 8-Mile, 16-Mile, and 50k. The park offers a stunning backdrop with diverse landscapes, incl..

The Thumbs Up Vertical Challenge is an exciting running event held in Estes Park, CO, featuring an 8-hour ascent on the Thumb Open Space trail. Participants will complete an out-and-back course, collecting poker chips at the turnaround to determine their placing. Unique patches are awarded for reach..

Santa's Summit Slam is a versatile running event that takes place in various weather conditions, featuring a 5-mile course that includes 30% gravel roads and 70% single-track trails. Participants can expect a unique experience, whether running on dry trails, navigating sloshy paths with traction spi..

The Running Up for Air - Staunton Rocks is an endurance running event taking place at Staunton State Park in Pine, Colorado, on February 14-15, 2025. This event features various challenges, including 3, 6, 12, and 24-hour races, encouraging participants to run a marked 7.1-mile loop. The event aims ..

The Winter's End Snowshoe Races, hosted at Granby Ranch Resort in Granby, CO, is an exciting winter sports event designed for runners of all skill levels. Scheduled for March 8, 2025, the event features multiple race distances, including a marathon, 16-mile, 8-mile, and a 2-mile fun run. Participant..

Run The Ranch is an exciting trail running event taking place at Sylvan Dale Guest Ranch in Loveland, Colorado, on April 4-5, 2025. Participants can choose from six different race distances, including a 5K, 10K, and various timed trail runs ranging from 4 to 12 hours, with options for solo runners a..

The Rock Hawk Trail Races, part of the Bear Chase Race Series, take place in Castle Rock, Colorado, featuring distances of 50K, 25K, 10K, and 5K. Set against the scenic backdrop of Miller Park and Ridgeline Trail systems, the event offers a thrilling experience for both novice and experienced trail ..

The Greenland Trail Races, held annually in May at the Greenland Open Space in Larkspur, Colorado, features four race distances: 4 miles, 8 miles, 25K, and 50K. This event is known for its scenic trails with views of Pikes Peak, making it a popular choice for both novice and experienced runners. Par..

The Mountain Ridge Trail Race, celebrating its 11th year, offers a variety of distances including a 5K, 10K, Half Marathon, and 21-Mile race, all set in the scenic Highlands Ranch, Colorado. Participants will enjoy 100% dirt and single-track trails with manageable elevation gains, showcasing the stu..

Niwot's Challenge is a challenging ultramarathon held annually in Colorado's Front Range, designed for experienced runners. Modeled after the Barkley Marathons, this grassroots event features a secretive course that requires participants to navigate using a map and compass, with limited aid availabl..

Samson's Revenge is a trail running event held at the YMCA of the Rockies in Estes Park, Colorado, honoring the legacy of Samson, a famous elk poached in 1995. Participants can choose from three distances: 10K, 27K, and 55K, featuring a challenging course with significant elevation gain, particularl..

The Endure Trail Runs, hosted by the Human Potential Running Series, takes place at Mueller State Park in Divide, Colorado. This unique event features a variety of races, including a 10k, Half Marathon, and timed challenges of 12 and 24 hours. Participants in the 12-Hour event will draw colored ball..

The Weld Your Mettle Running Festival is a vibrant event taking place from May 23 to May 25, 2025, in Eaton, Colorado. It features a variety of running challenges, including timed relays (3, 6, 9, 12, and 24 hours), a 7K Ruck, and a 1 Mile Kids Fun Run. Participants can enjoy a supportive community ..

The Ol' College Try 24 Hour Ultra is Denver's inaugural 24-hour ultra race, taking place at Auraria Campus on May 24-25, 2025. Organized by Rise Again Running Events in collaboration with Tall Tales Ranch, this event invites runners of all levels to challenge themselves in a non-stop race environmen..

The North Fork 50 Mile/50K is an ultramarathon set in the scenic Colorado mountains near Denver, taking place on May 31, 2025. This event features a challenging course that is entirely on soft surfaces, primarily singletrack trails, with some double track sections. Runners will experience diverse la..

The Crazy Legs 10k+ Trail Run is an exciting running event taking place at Devil’s Backbone Open Space in Loveland, Colorado, on June 1, 2025. This trail run features a challenging course designed to provide a fun experience for participants. Runners will navigate through various trails, with water ..

The Great Divide Ultra is a premier trail running event held in Divide, Colorado, featuring a variety of race distances including 100 miles, 100K, 50K, and 25K, taking place on June 7-8, 2025. Set in the scenic Mueller State Park, participants will experience beautiful rolling meadows and stunning v..

Estes Park's Backyard Ultra is a unique ultra-running event set against the stunning backdrop of Lake Estes, Colorado. Participants must complete a distance of 4.252 miles within one hour, every hour, until only one runner remains. This format continues without a predetermined end, making it a true ..

The Barr Lake Trail Race, held in Brighton, Colorado, is a celebrated running event now in its sixth year, featuring a variety of distances including 50K, 30K, Half Marathon, 15K, and 5K. Known for its flat and fast course with minimal elevation gain, the race offers stunning views of Barr Lake and ..