Colorado Running Races

363 upcoming races across Colorado in the next 12 months, from local 5Ks to marathons and ultras. Updated nightly. Want filters, maps, and radius search? Open Colorado in the Race Finder.

By distance: Marathons · Half Marathons · 5K Races · 10K Races · Ultras

By city: Denver · Colorado Springs · Centennial · Fort Collins · Arvada · Westminster · Grand Junction · Estes Park · Pueblo · Littleton

Racing in Colorado: what the calendar looks like

There are 363 races on the Colorado calendar over the next 12 months, which works out to roughly 7 per week. Among complete calendar months, November 2026 has the most listed races (79); September 2027 has the fewest (15). The busiest places to race are Denver (42), Colorado Springs (38), Centennial (25).

Of those, 239 offer a 5K, 117 offer a 10K and 107 offer a Half Marathon. The next marathon is Blue Sky Trail Marathon & Half Marathon on October 17 in Fort Collins. The next half marathon is Blue Sky Trail Marathon & Half Marathon on October 17.

By race count Colorado ranks 16th of 51 states and DC.

Races by month

October 2026

November 2026

December 2026

January 2027

February 2027

March 2027

April 2027

May 2027

June 2027

July 2027

August 2027

September 2027

October 2027

Planning a race

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