IRONMAN 70.3 Boulder
2024-06-08, 2025-06-14 | Boulder Reservoir, 5275 Reservoir Road, Boulder, CO, 80301, United States
Presale Registration for 2023 IRONMAN 70.3 Boulder opens at 10am MT on Thursday, August 4, 2022.

Loveland Lake to Lake Triathlon
2024-06-22, 2025-06-21 | North Lake Park (Loveland), 2750 N. Taft Ave., Loveland, CO, United States
This event provides a beautiful venue. The transition area and lake are near North Lake Park. North Lake Park is a nice setting for competitors and families. It has a children’s train that operates throughout the day and is adjacent to Benson Sculpture Park, which is the site of Loveland’s annual Sculpture in the Park each August.

Boulder Sunrise Triathlon
2024-06-23, 2025-06-29 | Boulder Reservoir, 5275 Reservoir Road, Boulder, CO, 80301, United States
Kick off your summer of racing in Boulder.

LG Triathlon
2024-07-13 | Gypsum, Gypsum, CO, United States
Join us on Saturday, July 13, 2024, for the 16th Annual LG Tri, a sprint triathlon in the beautiful Vail Valley town of Gypsum, Colorado. The course features a 500-yard open water swim, a 12-mile bike ride, and a 5K run. Adults can race as individuals or form a team. We’re also running the 12th annual Kids Tri, so bring the whole family! We’re excited to collaborate with the Siena Valley Club neighborhood — just a short drive from Eagle County Airport.

Boulder Peak Triathlon
2024-07-14, 2025-07-13 | Boulder Reservoir, 5275 Reservoir Road, Boulder, CO, 80301, 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, boasting an average 15% grade on their way to the finish line! This race has earned it’s spot on more than a couple notable “Best Triathlons in America” lists. In 2017, the Boulder Peak was listed as one of the top 15 most amazing triathlons in the United States by The Culture Trip!

Tri Boulder
2024-07-20, 2025-07-19 | Boulder Reservoir, 5275 Reservoir Road, Boulder, CO, 80301, United States
As one of Colorado’s most popular summer triathlons, Tri Boulder offers many different multisport race distances, all in one eventful day! Join us for a full day of racing at the Rez.

Steamboat Lake Triathlon
2024-07-28, 2025-07-27 | Steamboat Lake State Park, 61105 County Road 129, Clark, CO, 80428, United States
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, this lake, and the overall experience. The swim starts out in the surprisingly warm waters of Steamboat Lake (74 degrees average race temp), then athletes transition to the most scenic bike course you’ll ever find. You’re more likely to see a herd of cattle crossing the road than be passed by a vehicle! After a ride through the rolling country-side athletes will transition to a 3.5 mile run course that’s 50% on road, and 50% on the dirt trails that hug the lakeside. When we tell athletes you’re running through wild flower meadows, we’re not exaggerating.
Pack the camping gear and make a weekend getaway for your all your friends and family! This year we’re also offering a aquabike, and stand-up paddle-board division!

Stagecoach Gravel Triathlon
2024-08-04, 2025-08-03 | Stagecoach Reservoir (Steamboat Springs), 25500 County Road 14, Oak Creek, CO, 80467, United States
We didn’t get the chance to launch this race in 2020, but that didn’t diminish our passion for this brand new style of triathlon! To say this race is “unique” would be an understatement! Limited to just 250 athletes, we’re excited to announce the first ever gravel triathlon to the Colorado triathlon landscape! This event is set at Stagecoach Reservoir, a quiet and picturesque lake just 15min south of Steamboat Springs, with camping options for the entire family.
After the swim in the waters of Stagecoach Reservoir, it’s time to bring out either the gravel bike, road bike, or mountain bike. Just leave your triathlon bike at home. The course starts out with a short-paved section of 2.1 miles, before transitioning to rolling gravel country roads through some of the most scenic terrain imaginable. The total bike distance is 16 miles, with the final 3 miles of the course on pavement as athletes head back towards the transition area! Once off your bike of choice, it’s time to toss on those running shoes for a 4-mile run on a gravel trail that hugs the shoreline of Stagecoach Reservoir, (Note: ½ mile total on paved roads)! Come join us for this one of a kind triathlon experience, complete with a stand-up paddle-board option for the non-swimmers!

Outdoor Divas Sprint Triathlon
2024-08-18, 2025-08-10 | Union Reservoir (Longmont), 461 County Road 26, 80504, United States
The Outdoor Divas Sprint Triathlon features a half mile lake swim, a flat and fast single loop 12.4 mile bike, and finishes with a 3.1 mile run on a gravel road that hugs the lake.

Boulder Sunset Triathlon
2024-08-24, 2025-08-23 | Boulder Reservoir, 5275 Reservoir Road, Boulder, CO, 80301, United States
Join us for an unforgettable morning at the Boulder Reservoir. Although this race does not take place at sunset, it will take place at the end of the summer– it’s sister race is the Boulder Sunrise in June. Experience gorgeous views at the recently upgraded venue. All participants receive stellar race shirts and finisher medals, too. This race is a favorite for beginners due to the flat bike course and a packed dirt trail run course.

Littlefoot Triathlon
2024-09-07, 2025-09-06 | Bear Creek Lake Park (Lakewood), 15600 W. Morrison Road, Lakewood, CO, 80228, United States
Enjoy a fun late season tri at beautiful Bear Creek Lake Park in the Lakewood/Morrison area. Set at the base of the foothills, the Littlefoot Triathlon starts off with a 750 meter swim in Soda Lake, with water temps expected to be approximately 70 degrees. Next, a rolling bike 15K bike ride that covers nearly the entire park, offering great views throughout! Finish it up with a scenic 5K run on a bike path that winds through the park.

Lake Nighthorse Sprint & Olympic Triathlons
2024-09-07 | Lake Nighthorse, 1795 C.R. 210, Durango, CO, 81301, United States
Sprint Distance Triathlon – 750M Swim, 20km Bike, 5km Run
Olympic Distance Triathlon – 1500M Swim, 40km Bike, 10km Run

Oktoberfest Sprint Triathlon
2024-09-22 | Union Reservoir (Longmont), 461 County Road 26, 80504, United States
The Oktoberfest Sprint Triathlon features a half mile lake swim, a flat and fast single loop 12.9 mile bike, and finishes with a 3.1 mile run on a gravel road that hugs the lake. Please see course maps for a full description. Overall this is a beginner friendly course, and sets up very well for family and friends to spectate right alongside the action. The best part of Union Reservoir is how close the transition area, start line, finish line, expo area, and parking are to each other!

IRONMAN World Championship - Women's Race
2024-09-22 | Nice, France, Nice, France
The very best will embark on a 140.6-mile journey that presents the ultimate test of body, mind and spirit. Through decades of stellar athlete performances, inspirational participants and emotional memories, the IRONMAN World Championship has etched a reputation as the pinnacle of the triathlon landscape and an iconic global sporting event.

Last Call Triathlon
2024-09-29 | Boyd Lake State Park (Loveland), 3720 N County Road 11-C, Loveland, CO, 80538, United States
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, great weather and a family fun venue! Did we mention camping? Yup! There’s that too. Sitting on the east side of Loveland and southeast of Fort Collins, this close-to-home race day will have a family feel that’s intimate, fun and uniquely challenging. The course layouts make race morning packed with spectator cheering and multiple athlete flybys. With ON-SITE camping options, make a weekend out of this event and plan some extra relaxation time.

IRONMAN World Championship - Men's Race
2024-10-26 | Kailua-Kona, Hawaii, Kailua-Kona, HI, 96740, United States

Ordinary Mortals Triathlon
2025-05-10 | Pueblo, 2200 Bonforte Blvd, Pueblo, CO, 81001, United States
Ordinary Mortals Triathlon (OMT) is a reverse order sprint distance (5 km run, 12.5-mile bike, 300-yard pool swim) triathlon for all us “Ordinary Mortals” – from the first time triathlete to more competitive triathletes on a fun and challenging course.
Bring the kids for the youth triathlon, Mini Mortals Triathlon, after the adult race. This is a family friendly event often attracting several families of two or three generations racing together the same day!

Colorado Triathlon
2025-06-07 | Boulder Reservoir, 5275 Reservoir Road, Boulder, CO, 80301, United States
Colorado Sprint Triathlon: 750 meter swim, rolling and fast 17 mile bike, and finishes with a 3.1 mile run
Colorado Olympic Triathlon: 1500m swim, 23.5 mile bike, and a 10k run
Colorado Olympic Duathlon: 5k run, 23.5 mile bike, and a 10k run
Colorado Aquabike: Will feature a 1500 meter swim and a 24.8m bike

LG Triathlon
2025-07-12 | Gypsum, Gypsum, CO, United States
Join us for the Annual LG Tri, a sprint triathlon in the beautiful Vail Valley town of Gypsum, Colorado. The course features a 500-yard open water swim, a 12-mile bike ride, and a 5K run. Adults can race as individuals or form a team. We’re also running the 12th annual Kids Tri, so bring the whole family! We’re excited to collaborate with the Siena Valley Club neighborhood — just a short drive from Eagle County Airport.

Desert's Edge Triathlon Series
2025-09-13 - 2025-09-14 | Highline Lake State Park, 1800 11.8 Road, Loma, CO, 81524, United States
Desert’s Edge Triathlon Series features two days of racing, including Sprint and Olympic distance road triathlons, and a sprint off-road triathlon for open and collegiate racers.
