Trail Run races in Denver–Boulder, CO

Looking for trail races near you in Denver–Boulder, CO? There are 12 upcoming trail races listed here. The next one is RexRun For PAWSitivity 2026 Trail Run/Walk on Sat, Aug 29, 2026 at Arapahoe County Fairgrounds — see the full list below for dates, venues, and registration links, and browse trail races in other cities.

• Sat, Aug 29, 2026 RexRun For PAWSitivity 2026 Trail Run/Walk Arapahoe County Fairgrounds · Aurora, CO · From $20 5KTrail Run Trail
• Sat, Sep 5, 2026 Raising the Barr 13401 Picadilly Rd · Brighton, CO · From $55 Trail Run Trail
• Fri, Sep 11, 2026 Flaming Foliage Relay - Idaho Springs to Buena Vista 1545 Miner Street · Idaho Springs, CO · From $623 Trail Run Trail
• Sun, Sep 13, 2026 Buffalo Bicycle Classic University of Colorado Boulder · From $125 Half MarathonTrail Run Trail
• Sat, Oct 3, 2026 HRCA Wildcat Mountain Trail Races 11033 Monarch Blvd · Littleton, CO · From $10 10KTrail Run Trail
• Sun, Oct 4, 2026 Evergreen Mountain Weeknight Race 5300 S Olive Rd, · Evergreen, CO · From $25 Trail Run Trail
• Sat, Oct 10, 2026 Suffer Better 10th Annual Fall Trail Runs Staunton State Park · Pine, CO · From $25 5KTrail Run Trail
• Sat, Oct 17, 2026 Indian Creek Trail Runs 2499 Pine Creek Rd · Sedalia, CO · From $30 5KTrail Run Trail
• Sat, Oct 17, 2026 The Great Trailhead Foot Race 5 & 10 Miler 15600 W Morrison Rd. · Lakewood, CO · From $55 Trail Run Trail
• Sat, Nov 7, 2026 Turkey Trails- Denver Chatfield State Park · Littleton, CO · From $17 5K10KHalf MarathonTrail Run Trail
• Sat, Dec 5, 2026 Sawmill Trail Runs 12102 S Elk Creek Rd · Pine, CO · From $60 Trail Run Trail
• Sat, May 1, 2027 Greenland Trail Races 1532 E Noe Rd · Larkspur, CO · From $25 5KTrail Run Trail

New to the distance? Read trail vs. road racing, or set your target with the pace chart.