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Whether a race, special group ride, training opportunity, or cycling-related community event, the 303 calendar showcases it all.  To have an event posted here please follow this link:  Event Policy Submission & Guidelines.

Boulder Peak Olympic

Boulder Reservoir Boulder

The Boulder Peak Triathlon, Duathlon & Aquabike on July 11th is one of the countries longest and most well-known triathlons.  For the veteran or first time racer, this is THE can’t missRead More

Tri Boulder, Sprint, Olympic, Long

Boulder Reservoir Boulder

As one of Colorado’s most popular summer triathlons, Tri Boulder offers many different multisport race distances, all in one eventful day; Long Course, Olympic and Sprint Triathlon, Sprint Duathlon andRead More

Steamboat Lake Sprint, Aquathon

steamboat Lake

After last summer this event instantly became a personal favorite for our staff, volunteers, and athletes - come find out why!  We couldn't be more excited about this course, thisRead More

Steamboat Triathlon


The Steamboat Triathlon features a sprint distance, olympic distance, aquabike, Olympic distance duathlon, & stand-up paddle-board options.  The swim starts off in the picturesque Lake Catamount.  Triathletes will then quickly transitionRead More

Outdoor Divas Sprint

The Outdoor Divas Sprint Triathlon on August 22nd, annually awarded best women's event in Colorado by Competitor Magazine, is the all women's triathlon you've been waiting for!  We intentionally keepRead More

Boulder Sunset Tri, Sprint, Olympic,

Boulder Reservoir Boulder

Olympic Triathlon 1500m swim / 26.4 mile bike / 6.2 mile run. Sprint Triathlon 750m swim / 17.3 mile bike / 3.1 mile run! Olympic Aquabike 1500m swim / 26.4Read More

Harvest Moon

Boulder Reservoir Boulder

The Harvest Moon Triathlon the 21st edition of this event takes place at the beautiful Boulder Reservoir on September 11th, 2021.  Est. in 2000 this Colorado classic  provides the veterans to beginners a challenging,Read More

Oktoberfest Sprint

Union Reservoir Longmont

The annual Oktoberfest Triathlon on September 19th, 2021,  is the party of the season and also a 2021 Mountain Collegiate Conference Race!  As the leaves change color this race will officially end the Colorado Triathlon Season!Read More

TriBella Womens Sprint

Cherry Creek State Park 4201 S Parker Rd, Aurora

The TriBella Women's Triathlon, presented by Coeur Sports, is the perfect all women's triathlon for first time triathletes looking to try the sport out, or seasoned veterans looking for a funRead More

Last Call Sprint

Boyd Lake Loveland

Yes! I want ONE MORE adventure!! Escape to the lake! The Last Call Triathlon will be an event you’ll look forward to all season long. Why? Beautiful mountain views, greatRead More