September 2026 races in Denver–Boulder

There are 35 running events listed in Denver–Boulder for September 2026 — 31 5K, 11 10K, 8 Half Marathon, 1 Marathon, 3 Trail Run — starting with Raising the Barr on Sat, Sep 5, 2026. Every listing shows the date, venue, and distances, with a direct link to registration.

• Sat, Sep 5, 2026 Raising the Barr 13401 Picadilly Rd · Brighton, CO · From $55 Trail Run Trail
• Sat, Sep 5, 2026 Golden Harvest Half Marathon & 5k/10k - Denver Parking Lot South of The Westin Westminster · From $17 5K10KHalf Marathon Road
• Sat, Sep 5, 2026 Demon Dash 19500 W 64th Pkwy · Arvada, CO · From $25 5K Road
• Mon, Sep 7, 2026 Labor Day Half Marathon Salisbury Equestrian Park · Parker, CO · From $27 5K10KHalf Marathon Road
• Mon, Sep 7, 2026 FCA All-Abilities Labor Day 5K Mehaffey Park 3350 W 29th Street · Loveland, CO · From $10 5K Road
• Fri, Sep 11, 2026 Flaming Foliage Relay - Idaho Springs to Buena Vista 1545 Miner Street · Idaho Springs, CO · From $623 Trail Run Trail
• Sat, Sep 12, 2026 National Chocolate Day: Run for Chocolates 5K/10K/13.1 DENVER/AURORA Piney Creek Hollow Park (Course Map will be emailed) · Centennial, CO · From $30 5K10KHalf Marathon Road
• Sat, Sep 12, 2026 Run for Mental Health 5K/10K/13.1 DENVER/AURORA Piney Creek Hollow Park (Course Map will be emailed) · Centennial, CO · From $30 5K10KHalf Marathon Road
• Sat, Sep 12, 2026 6 Dot Dash 2233 W Shepperd Ave · Littleton, CO · From $40 5K Road
• Sat, Sep 12, 2026 For The City Network 5K 1501 65th Ave · Greeley, CO · From $35 5K Road
• Sat, Sep 12, 2026 The Denver 5k Utica Street & West 17th Ave · Denver, CO · From $35 5K Road
• Sun, Sep 13, 2026 Mad Dash 5K 2100 Country Club Parkway · Milliken, CO · From $40 5K Road
• Sun, Sep 13, 2026 RMRR September 5k/10k 9830 Riverdale Road · Thornton, CO · From $10 5K10K Road
• Sun, Sep 13, 2026 Buffalo Bicycle Classic University of Colorado Boulder · From $125 Half MarathonTrail Run Trail
• Sun, Sep 13, 2026 31st El Grito 5k (2026) 900 Auraria Parkway · Denver, CO · From $20 5K Road
• Sun, Sep 13, 2026 Tiger Prowl 5K 9700 W 8th Ave · Denver, CO · From $20 5K Road
• Sun, Sep 13, 2026 9/11 Heroes Run - Denver, Colorado Great Lawn Park · Denver, CO · From $21 5K Road
• Sat, Sep 19, 2026 All-Out Fall Fest 10170 Church Ranch Way · Westminster, CO · From $35 5K10KHalf Marathon Road
• Sat, Sep 19, 2026 14th Annual Superhero Event Family Fun Plex or Anytime/Anywhere Virtually · Greeley, CO · From $20 5K10K Road
• Sat, Sep 19, 2026 Gummball 5K 9755 Henderson Road · Brighton, CO · From $30 5K Road
• Sat, Sep 19, 2026 Miles 4 Madison 5K & 1K 8100 Piney River Ave · Littleton, CO · From $25 5K Road
• Sat, Sep 19, 2026 2026 Montbello Alive! 5K 15555 E. 53rd Ave · Denver, CO · From $25 5K Road
• Sat, Sep 19, 2026 Denver: Walk With Autism and Resource Fair 4601 W 46th Ave · Denver, CO · From $25 5K Road
• Sun, Sep 20, 2026 Expo Park XC Runs South Moline St and East Exposition Ave. · Aurora, CO · From $22 5K Road
• Sun, Sep 20, 2026 20th Annual Golden Gallop 701 24th St · Golden, CO · From $25 5K10K Road
• Sun, Sep 20, 2026 Farmers 5000 9505 W. 32nd Ave · Wheat Ridge, CO · From $10 5K Road
• Sat, Sep 26, 2026 Oktoberfest Run 5K/10K/13.1 DENVER/AURORA Piney Creek Hollow Park (Course Map will be emailed) · Centennial, CO · From $30 5K10KHalf Marathon Road
• Sat, Sep 26, 2026 Run for Donuts 5K/10K/13.1 DENVER/AURORA Piney Creek Hollow Park (Course Map will be emailed) · Centennial, CO · From $30 5K10KHalf Marathon Road
• Sat, Sep 26, 2026 Lisa Nelson’s Mustang Stampede 5K 13355 West 80th Avenue · Arvada, CO · From $25 5K Road
• Sat, Sep 26, 2026 Parker Parks and Recreation So Long to Summer 5K/10K 11920 Motsenbocker Rd · Parker, CO · From $40 5K10K Road
• Sat, Sep 26, 2026 Runway 5K - Run for the Angels 11001 Control Tower Road · Broomfield, CO · From $40 5K Road
• Sat, Sep 26, 2026 HRCA Oktoberfest 5K 9352 Dorchester St · Littleton, CO · From $40 5K Road
• Sun, Sep 27, 2026 NIGHT NATION RUN - DENVER DICK'S SPORTING GOODS PARK · Commerce City, CO · From $35 5K Road
• Sun, Sep 27, 2026 Boulder Marathon Boulder Reservoir Marathon Road
• Sun, Sep 27, 2026 Flyin' Lion 5K 199 E. Littleton Blvd. · From $15 5K Road

Quick answers

How many races are there in Denver–Boulder in September 2026?

35 running events are listed in Denver–Boulder for September 2026, from Raising the Barr on Sat, Sep 5, 2026 to Flyin' Lion 5K on Sun, Sep 27, 2026. Every listing links directly to registration.

What distances can I race in Denver–Boulder in September?

The September 2026 calendar in Denver–Boulder includes 31 5K, 11 10K, 8 Half Marathon, 1 Marathon, 3 Trail Run.

What is the first race of September 2026 in Denver–Boulder?

Raising the Barr on Sat, Sep 5, 2026 at 13401 Picadilly Rd.