Trail Running calendar near Castle Rock 2026-2027

Trail races of 5k, 10k and half marathon on Frisco Peninsula trails with single track, lakeshore finishes, chip timing, aid stations for the 10k and half, and post race food and beer for participants 21 and older.

The 21st Annual Reece's Roundup is a trail run and one-mile walk on August 8 at Philip S. Miller Park in Castle Rock, CO. Proceeds support a benefit fund for a child living with Spinal Muscular Atrophy.

Trail run at Rampart Reservoir with 8 mile and 16 mile options on single track and rocky sections. Entry is limited to 150 and registration closes August 5, 2026.

A traditional pack-burro race in Leadville, Colorado at over 10,000 feet where each team is one runner and one burro carrying mining tools. The long course is about 21 miles and a shorter 6 to 8 mile course is planned.

STRS #5 Carter Park Scurry in Breckenridge on August 12 2026 offers short and long course entries across adult youth and non-binary divisions with published entry fees and a course map.

A mostly dirt and trail race along Boulder Reservoir in Boulder, Colorado, with about 200 feet of elevation gain. Distances range from a 10K to a full marathon, plus a relay option.

Trail ultras from Roxborough State Park to Sharptail Trailhead featuring sustained climbs, technical singletrack, and a long runnable finish, with full aid support and an emphasis on land stewardship.

Experience the trails of Cheyenne Mountain State Park with three race distances ranging from a 5K walk to a 25K mountain challenge. This chip timed fundraiser supports park conservation through scenic and high elevation courses.

Westminster Trail Race at Standley Lake on August 15, 2026 offers five distances from 5K to 50K on 100% dirt trails with out and back course formats, elevation gain, on course support, and parking at Wayne Carle Middle School.

Summit Grays and Torreys Peaks in this 8.8 mile Colorado endurance event. Participants must carry a 20lb dry load while tackling 4,101 feet of elevation gain.

A high-altitude 10K in Leadville on August 16, 2026 that follows the first and last 3.1 miles of the LT100 Run course on paved and dirt roads. One aid station is provided and awards will be given in overall, para and age categories.

The Rocky Mountain Milestone Challenge will take place in Granby from Wednesday 19 August 2026 to Sunday 23 August 2026. You can run between 13 and 100 miles.

A 99.7 mile out‑and‑back ultramarathon in Leadville, Colorado, across forest trails and mountain roads with 15,492 feet of elevation gain and a 12,526 foot high point at Hope Pass. Finishers under 25 or 30 hours receive a belt buckle.

Experience a high altitude trail run through the Rocky Mountains on 100 percent unpaved roads and trails. This dog friendly event in Fraser supports children facing cancer through the Shining Stars Foundation.

A trail race at Staunton State Park offering 26.3 mile and 13.1 mile courses over mostly singletrack with significant elevation gain, well marked trails, capped fields, and fully stocked aid stations.

A half marathon trail race in Evergreen, CO that reaches the summit of Bergen Peak. Organized by the local parks district, the event includes vendor tents, refreshments, a cup-free policy and course marshals.

Rock Hawk in Castle Rock, Colorado runs on the Miller Park and Ridgeline trails with 50K, 25K, 10K and 5K options. The event features cup-free aid stations, drop bags, chip timing and live split tracking.

A community trail event at the Arapahoe County Fairgrounds on 08/29/2026 with a 5K run, a family 5K walk that allows leashed dogs, and a kids 1 mile plus demonstrations, vendors, and a pancake breakfast.

Run Like the Wind in Allenspark on August 29, 2026 features a 5K race, a 2K run/walk and a dog jog option. Proceeds benefit The Old Gallery and participating dogs are entered in an amateur dog show.

A 5k trail run starting at 11,000 feet at Copper Mountain on August 29, 2026, presented by Mammut. The run takes place during the Union Peak Festival, which includes live music and festival activities afterward.