70.3 Boulder

Saturday 13 June 2026
Add To Calendar
US Boulder, Colorado, United States
Ironman 70.3 Boulder will be held at the Boulder Reservoir. The race, the first-ever Ironman 70.3 in the region, will bring spectacular views of the Rocky Mountains, a challenging course, solid competition and strong volunteer support. Ironman 70.3 Boulder will serve as one of more than 35 worldwide qualifying events for next year's Foster Grant Ironman World Championship 70.3 in Clearwater, Fla. Swim: 1.2 miles The swim will consist of one lap in the Boulder Reservoir. The start will be from the right (or east) of the public swim area, and the finish will be past the Pavilion Building, directly "above," or north, of the Transition Area. Bike: 56 miles The course starts at the Boulder Reservoir parking lot, heads south on 51st to Jay road and west to Highway 36. Rolling along 36 north towards Lyons , the first aid station is at mile 6. Continue along 36 and turn east on St. Vrain Road . Enjoy the smooth pavement downhill of St. Vrain Road to where it "t's" at 75th Street. Make a right on 75th, and continue all the way as it turns into 73rd. We will make a right turn on Monarch Road (at IBM), going down Monarch for 0.6 mile before making a u-turn back to 73rd. Once back at 73rd, make a right and continue to the Diagonal. This turnaround on Monarch will be done on both loops. Head south west on the Diagonal toward Boulder , Right on Jay road, and continue on Jay for the second loop on the same route. When you reach Jay and 51st after your second loop, make a right and return north on 51st street back to the Reservoir. Run: 13.1 miles The start is at the bike transition area on the south side of the Reservoir near the main pavilion. Run west on the asphalt/gravel to the front gate. Turn right and continue north on 55th Street, passing Monarch road, going about halfway to Niwot Road. Turn around at the Turn-Around marker, go back to Monarch Rd. and turn left and head east on Monarch to the Canal Road entrance. Pick up the canal road and head south around the


Coming Triathlon Events View all

Challenge Almere Amsterdam

Almere Haven, Netherlands

Blacklake Xtreme

Zabljak, Montenegro

Estrela Xtreme

Manteigas, Portugal

le man full distance

Evian, France

BearMan Xtreme

Amélie-Les-Bains, France

Triathlon de Saint Cirq Lapopie

Saint Cirq Lapopie, France

Triman 226

Olympic Beach, Greece

Elbaman

Elba Island, Italy

Infinitri 226

Peñíscola, Spain

Ironcat

I`Ampolla, Spain

IRONMAN WORLD CHAMPS MEN

Nice, France

Ironman Japan South Hokkaido

Hokkaido, Japan

Ironman Italy

Cervia, Italy

Ironman Maryland

Cambridge, Maryland, United States

Ironman Wales

Tenby, Wales, United Kingdom

Ironman Gurye Korea

Gurye, Korea, Republic of

Ironman Chattanooga

Chattanooga, TN, United States

Ironman Barcelona

Barcelona, Spain

IRONMAN WORLD CHAMPS WOMEN

Kailua Kona, Hawaii, United States

Ironman Portugal Cascais

Cascais, Portugal

Triathlon de Royan

Côte de Beauté, France

South Carinthian Triathlon

Sankt Kanzian am Klopeiner See, Austria

Toughman

Lake Welch Beach, Stony Point, NY, United States

Barrelman

Niagara Falls, Canada

Vitruvian

Rutland water, United Kingdom

Alpha Win Saugerties

Saugerties NY, United States

Sandman

Newborough Forest, United Kingdom

Wildman

Lawrenceburg KY, United States

Challenge Sanremo

Sanremo, Italy

Dirty Mitten

Lake Barlow MI, United States

70.3 Sunshine Coast

Mooloolaba, Australia

70.3 Weymouth

Weymouth, United Kingdom

70.3 Michigan

Frankfort MI, United States

70.3 Erkner

Brandenburg, Germany

70.3 New York

Jones Beach, NY, United States

70.3 Italy Emilia Romagna

Cervia, Italy

70.3 Sao Paulo

São Paulo, Brazil

70.3 Western Sydney

Penrith, NSW, Australia

70.3 Cozumel

Cozumel, Mexico

70.3 Washington Tri Cities

Richland, Washington, United States

Triathlon News & Media Blogs View all

Tamara Jewett CAN, Sam Appleton AUS Win 70.3 Santa Cruz California

Tamara Jewett CAN, Sam Appleton AUS Win 70.3 Santa Cruz California

Monday 08 Sep 2025 [Triathlon News]

On Sunday, September 7, 2025, Australian Sam Appleton and Canadian Tamara Jewett both set new course records to win the Ironman 70.3 Santa Cruz. Both elite athletes overcame strong fields to dominate the men's and women's professional divisions, respectively. more

Cameron Main GBR, Diede Diederiks NLD Win 70.3 Nokke Heist Belgium

Cameron Main GBR, Diede Diederiks NLD Win 70.3 Nokke Heist Belgium

Monday 08 Sep 2025 [Triathlon News]

At the Ironman 70.3 Knokke-Heist on September 7, 2025, Cameron Main of Great Britain and Diede Diederiks of the Netherlands claimed the professional victories. Both athletes put on a dominant display, with Diederiks making up a significant deficit on the bike and Main leading the men's race from the front. more

Rebecca Anderbury GBR, Valdemar Solok DEN Win 70.3 Poznan Poland

Rebecca Anderbury GBR, Valdemar Solok DEN Win 70.3 Poznan Poland

Monday 08 Sep 2025 [Triathlon News]

Athletes and spectators enjoyed a weekend of events that included a children's bike race and an expo, despite some rainy weather earlier in the week. The race featured a swim at Lake Kierskie and a scenic course through the Greater Poland region before the finish in Poznan. more

IRONMAN Jacksonville Florida Set to Debut in 2026

IRONMAN Jacksonville Florida Set to Debut in 2026

Thursday 04 Sep 2025 [Triathlon News]

IRONMAN, the global leader in long-distance triathlon, announced today the addition of a new full-distance IRONMAN® triathlon in northeastern Florida to the global circuit. The inaugural edition of the IRONMAN Jacksonville triathlon is scheduled to take place on Saturday, May 16, 2026, with a swim, bike, and run course that will take athletes through downtown Jacksonville passing into Duval and Nassau Counties. more

70.3 Santa Cruz California Pro Start List

70.3 Santa Cruz California Pro Start List

Thursday 04 Sep 2025 [Triathlon News]

Santa Cruz embodies the laid-back, sandy-feet, “no shirt, no problem” culture that makes the California Coast so uniquely… California. Even passionate, driven triathletes (who’ve made Type 2 fun an art) pause their watches to take in the September sunset over the harbor. IRONMAN 70.3 Santa Cruz has a long history in Santa Cruz, merging a chill, local-race feel with the high-end IRONMAN experience athletes expect. more

Facebook


YouTube


Sign up for FREE NEWSLETTER:

We will never share your email address or spam you.