-
Weld Your Mettle Running Festival
A timed mileage challenge with camping in Northern Colorado
-
Basalt Half Marathon & Relay
Descend 1,000 feet along the Frying Pan Road
-
Golden Gate Dirty 30
Through Golden Gate Canyon State Park's high country
-
The Great Divide Ultra
Rolling meadows and Pikes Peak granite in Mueller State Park
-
Runway 5K
Runs down the runways of Centennial Airport
-
-
-
Creede Donkey Dash
Runner and burro teams race through Creedes historic mining district
-
-
June 2026 Trophy Series - 4 km at Bible Park
Fast 4K loop at Denver's Bible Park
-
Steamboat Marathon
Yampa Valley miles beside the Elk River and Rocky Mountains
-
-
Stepping Stone 5K
Two laps round Johnson Reservoir at Clement Park
-
-
All-Out Summer Breeze
Flat miles along Arvada's Van Bibber Creek Trail
-
Howelsen Hill Trail Run
A trail run on Steamboat's historic ski jump hill
-
Summits Trail Runs
Alpine meadows, aspen groves, and big mountain vistas at Granby Ranch
-
Garden of the Gods Ten Mile Run
Fifty years of racing through the iconic Garden of the Gods
-
Red, White and Brew 5k, 10k & Half Marathon
Includes 5k and 10k military ruck divisions
-
Dash Across the Dam Father's Day 5K
Crosses the dam at Rueter-Hess Reservoir
-
Summer Solstice 10K & 5K
Climbs beside Beaver Creek's Centennial Lift
-
Ring the Springs
Starts at Rock Ledge Ranch Historic Site
-
-
Longs Peak 5 Miler
Lake Estes trail views of Longs Peak
-
San Juan Solstice 50 Mile Run
Fifty miles of alpine peaks and technical San Juan trails
-
-
Father's Day Classic 10k, 5k, & 1 Mile
Arvada's Father's Day race includes a men-only Manly Mile
-
Estes Park Marathon and Half Marathon
Forbes ranked top seven most scenic half marathon in the US
-
High Line Canal Summer Scamper
Runners follow Denver's 71-mile High Line Canal
-
Slacker Half-Marathon
Descend 2,480 feet from Loveland Ski Area to Georgetown
-
Chase the Moon
Overnight ultra under the full moon in Highlands Ranch
-
Leadville Trail Marathon
Climb to Mosquito Pass at 13,185 feet in historic Leadville
-
Before The Fourth 5k
Loops the perimeter of Johnson Reservoir
-
Timberview Trail Run
Treetop trail views over Horsetooth Reservoir
-
Blue Sky Ascent & Round Trip
Climbs the highest paved road in North America
-
Blue Sky Ascent
Climb nearly 4,000 feet to the 14,264-foot summit of Blue Sky
-
Boulder Sunrise 10K & 5K Run
Runs from Boulder Reservoir with Flatirons views
Save any of these to your season in RunCalendar and hear the morning entries open. Free on iPhone, no account needed.
Every race here is published by its organiser; RunCalendar checks the date and the entry window against the organiser's own page and rebuilds this calendar every night. A confirmed date shows its day; a provisional one shows only its month. Last updated 22 October 2026.