Overview
Race IRONMAN 70.3 Boulder with a stunning course featuring a reservoir swim, scenic mountain bike ride, and a run through Boulder’s picturesque trails and roads.
Overview IRONMAN 70.3 Boulder begins with a 1.2 mile swim in beautiful Boulder reservoir, a 56 mile bike traversing rolling hills along the iconic flatirons and then ends with a 13.1 mile run surrounded by family and friends. Maps are subject to change. Rise to the Challenge Iconic Flatirons. Beautiful Boulder. The outdoor playground for endurance athletes. Boulder caters to the outdoor enthusiast and not only provides epic trails and outdoor activities but also world-class dining, shopping, events and craft beer and spirits. Boulder gives you a taste of everything Colorado.
Race categories
113K
IRONMAN 70.3
- Schedule
Thursday, June 11, 2026
2 PM - 6 PM · Athlete Check-In & Timing Chip Pick-Up · Boulder Reservoir 2 PM - 6 PM · IRONMAN Village Information Tent PLAYTRI Triathlon Store & Tech Service Center VIP Spectator Credential Pick-Up · Boulder Reservoir 2 PM - 6 PM · Official IRONMAN Store · Boulder Reservoir 3 PM - 3:45 PM · Athlete Briefing · Boulder Reservoir 5 PM - 5:45 PM · Athlete Briefing · Boulder Reservoir 6 PM · Shake Out Run · The Rayback 2775 Valmont Rd, Boulder, COFriday, June 12, 2026
9 AM - 4 PM · Athlete Check-In & Timing Chip Pick-Up (AWA Priority Check-In Ends at 12 PM) · Boulder Reservoir 9 AM - 4 PM · IRONMAN Village Information Tent PLAYTRI Triathlon Store & Tech Service Center VIP Spectator Credential Pick-Up · Boulder Reservoir 9 AM - 4 PM · Official IRONMAN Store · Boulder Reservoir 9:30 AM - 4:30 PM · Mandatory Bike Check-In · Boulder Reservoir 11 AM - 11:45 AM · Athlete Briefing · Boulder Reservoir 2 PM - 2:45 PM · Athlete Briefing · Boulder ReservoirSaturday, June 13, 2026 - Race Day!
4 AM - 6 PM · Shuttle Service to/from Transition No dogs allowed at Boulder Reservoir or on the shuttle buses. Spectators will have shuttle access to the reservoir from 4:00 AM to 10 AM (athletes have priority). Due to permit/safety requirements, spectators may only ride into the reservoir during these hours. There will be no shuttle access into the Reservoir after 10 AM. · Kyndryl Boulder 6300 Diagonal Hwy 4:30 AM - 7 AM · Transition Open · Boulder Reservoir 7:05 AM · Race Start · Boulder Reservoir 8 AM - 4 PM · IRONMAN Village & Information Tent · Boulder Reservoir 8 AM - 4 PM · Official IRONMAN Store · Boulder Reservoir 10:30 AM - 5 PM · Athlete Post-Race Food · Boulder Reservoir 12 PM - 1:30 PM · Early Bird Bike & Gear Check-Out Access to transition will be metered by staff based on capacity of transition during this time. · Boulder Reservoir 12 PM - 6 PM · Post-Race Athlete Pickup · Boulder Reservoir 1:30 PM - 5 PM · Bike & Gear Check-Out · Boulder Reservoir 4:30 PM · Awards Ceremony & 2026 Precision Fuel & Hydration IRONMAN 70.3 World Championship Slot Allocation/Rolldown Ceremony Automatic Qualifiers need to be present during the Awards Ceremony to claim their slot with their award. Slot Allocation/Rolldown for the remaining age group “Performance Pool Slots” will begin immediately following Awards. Be early! Must be present to claim a slot. · Boulder Reservoir- Route
Swim
Reservoir
Bike
Hilly
Run
Hilly
Typical race-day conditions
Air 13–33 °C · Water 17 °CSwim course
This one-loop swim starts with athletes entering the Boulder Reservoir from the east boat ramp. The swim course is counterclockwise. Athletes will exit at the west boat ramp before heading towards transition.Bike course
The 2-loop course starts at the incredible Boulder Reservoir and will head onto Diagonal Hwy towards Foothills Hwy. Athletes will have some short rollers until they make a right onto rural Hygiene rd. towards 63rd St at which point, it’s downhill and fast. Once you find your way back onto Diagonal Highway, continue past the Reservoir gates for Lap 2, it's one more loop of the above rollers and fast descents.Run course
The run will showcase all the views along Boulder Reservoir with this 2-loop counter clockwise run. From transition, athletes will head east towards the Boulder Reservoir dam, head north along the trail, hop out onto 63rd for a small section and then a left on Monarch Rd for a nice hard packed dirt road full of downhill rollers. After Monarch, athletes head south on 55th (also packed dirt) where some of the best runners in the world train daily. Take a left back into the Boulder north entrance, pass transition area and head out for a 2nd loop. This 2-loop run course will be fast, downhill rollers around the 'Rez and along hard compact dirt roads.
Update history
3 Oct 2026
Time changed: 12 June at 0:00 → 12 June at 4:00
IRONMAN 70.3 Boulder
Sat, 12 Jun 2027