Trail Running calendar near Castle Rock 2026-2027

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.

Trail races around Standley Lake in Westminster, CO, with five distances on packed dirt trails and lake and mountain views. Organized by Aravaipa Running; registration closes Aug 10.

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 100-mile out-and-back ultramarathon in Leadville, Colorado with about 15,492 feet of climb, a summit at Hope Pass and 11 on-course aid stations.

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.

The Evergreen Trail Race Series will take place in Evergreen on Saturday 22 August 2026. You can run between 5 and 11 miles.

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 at Copper Mountain starting at 11,000 feet, held during the Union Peak Festival with music and festival activities afterward.

Multi-day ultrarunning event in Loveland, Colorado on a 2 mile loop with time-based options up to 100 hours and distance races to 200 miles. Continuous aid, chip timing, and camping are available.

The Cirque Series at Arapahoe Basin on Sept 5, 2026 is a 9.4 miles mountain trail race with 2,211 ft of ascent on approved White River National Forest trails. The field is capped at 600 runners and includes a branded hat, bib and medal.

Join the community for a 5K run or walk on a brand new dirt course at the North Arvada Middle School Athletic Complex. Support local high school racers before taking on this off road route yourself.

A load bearing endurance event at Staunton State Park on September 5, 2026. Routes range from 6.5 to 21.5 miles with loads from 10 to 40 lb and proceeds benefit the Special Forces Foundation.

A multi-distance running event in Longmont, CO on September 11-12, 2026, held on a 1.05-mile loop. Events range from a 100-mile race with a 30-hour cutoff to shorter runs, with aid stations, timing, and finish awards.

A longstanding Nederland, Colorado running event offering a 5K road run, a 10K trail, and a trail half marathon, with family-friendly features, on-leash dogs allowed in the 5K, and costume encouragement.