All-Out Dog Days – 5K, 10K and Half Marathon

Church Ranch Office Park 10170 Church Ranch Wy, Westminster, CO, United States

Get ready for some fun in the sun and a great mid-season test of your training as we bring our 11th Annual Dog Days 5K, 10K & Half Marathon! Centrally located between Denver & Boulder along with its Endless Series sidekick in December Fa La La, the beauty of our breathtaking Flatirons as a backdrop will inspire you […]

LG Triathlon

Siena at Brightwater 1000 Brightwater Club Drive, Gypsym, CO, United States

Can you keep a secret? Eagle, Colorado, is a special place, and they have a fantastic triathlon that you should not miss. They're calling for triathlon experts, newbies, and everyone in between, including the kids! Join them on July 9th for the 14th Annual LG Tri, a sprint triathlon held in the beautiful Vail Valley town of Eagle.

$40 – $150

I Can 5K

Riverdale Regional Park 9755 Henderson Road, Brighton, CO, United States

You CAN 5k. This event is for EVERY ONE. EVERY BODY. You won't get lost. You won't get forgotten. You'll run a clearly marked 5k loop with multiple portojohns & aid stations along the way. And if you're up for a 10k you'll be running the same loop one more time! We're going to keep […]

CMRA John Meade 6K

John Meade Park 2450 E Quincy Ave, Englewood, CO, United States

We will start with a loop of John Meade Park before heading onto the Cherry Hills Trail for an out-and-back short cirtcuiting the initial loop. This race will be ~3.875 miles (6k) with the same course for walkers and runners. ~115ft. The course is nearly all trail or gravel path with 0.2 miles of paved […]

SUP-Athlon

Cabin Creek Brewing 577 Twenty-Second Street, Georgetown, CO, United States

Looking for a new summer tradition suitable for all abilities?! Join us this July for the Georgetown SUP-Athlon! Participants will embark on a 0.5-mile stand-up paddleboarding journey along the scenic Georgetown Lake inlet, followed by a 5-mile road/gravel/dirt biking course around historic Georgetown. Finally, the 5k run will loop you around beautiful Georgetown Lake. Teams […]

Barr Lake Trail Race

Barr Lake State Park 13401 Piccadilly Road, Brighton, CO, United States

The Endurance Race Series heads back to Barr Lake State Park in Brighton, CO for some beautiful lake views and new PR's. This 6th Annual event showcases a course that is our flattest and fastest on the ERS schedule with less than 100' of elevation gain per loop. Runners will start and finish at the […]

Boulder Peak Triathlon

Boulder Reservoir 5565 N 51st St, Boulder, CO, United States

The Boulder Peak Triathlon, Duathlon & Aquabike on July 10th is one of the countries longest and most well-known triathlons.  For the veteran or first time racer, this is THE can’t miss event of the summer triathlon season, and the crown jewel of the Colorado Triathlon Series. Racers are tackling the infamous “Olde Stage” Hill, […]

Greenland Pack Burro Race

Greenland Open Space 1532 E Noe Rd, Larkspur, CO, United States

Welcome to the annual Greenland Open Space Pack Burro Races presented by Double Rainbow Ranch! Grab your burro and join us for a fun and rewarding day on the majestic Greenland Open Space Trail in beautiful Larkspur, Colorado. RACE RULES Each entrant will pay a fee as determined by the Race Director for each race. […]

High Lonesome 100

County Road 321 Nathrop, CO, United States

The High Lonesome 100 is a high flying endurance race in the Sawatch range of the Colorado Rocky Mountains. With 22,500' of vertical gain and reaching an elevation of 13,150', it's a hell of a course. The race runs in a loop through some of the most beautiful single track in the state, and takes runners on the Continental Divide and Colorado Trail, through 2 ghost towns, over 5 alpine passes, through remote basins, and over soaring ridges. This year's event takes place on July 30th.

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