Boulder Peak Triathlon
Boulder, United States · July · Independent
Why people love it
- Old Stage Road climb of about 183 m (600 ft) gives the bike its character.
- Reservoir swim, usually wetsuit-legal at 18 to 24 °C (64 to 75 °F).
- Aid every mile (1.6 km) on the 10 km (6.2 mi) dirt-road run.
- Boulder foothills views and a strong local triathlon scene.
- Boulder has good food and cycling culture for the rest of the weekend.
Watch out for
- Run can top 32 °C (90 °F) in July with little shade.
- Racing at 1,590 m (5,215 ft) slows athletes from lower elevations.
- Old Stage Road hits 12 to 16 percent early in the bike.
- Swim sighting into low morning sun can be hard.
- Olympic only in 2026, with no sprint, so a stretch for first-timers.
Race
How racers feel about it, how well it is run, and how it treats a first timer. Counts for 30% of the overall score.
Toughness: Very tough
- Racer satisfactionLoved3.8
Mostly upbeat reports across the years, with a 2019 racer pleased, but heat is a repeated complaint and few recent athlete reviews exist. · Low confidence
- OrganizationWell run3.5
A 2015 racer faulted the swim course and flimsy aid cups in the Life Time years. A 2019 racer found ample warm-up time. · Low confidence
- First timer friendlyDoable2.7
Olympic only, with a steep early climb, altitude and heat. A stretch for a first Olympic. · Low confidence
Course traits, not part of the score
- PR potentialAverage2.6
Early 183 m (600 ft) climb plus altitude and heat make it slower than flat Olympics. · Low confidence
Swim
Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 16% of the overall score.
- Wetsuit legalUsually4.1
Reservoir reported at 18 to 24 °C (64 to 75 °F). USA Triathlon allows wetsuits up to 25.6 °C (78 °F), and 2019 was wetsuit-legal. · Low confidence
- Water temperatureComfortable3.9
Reports range from about 18 °C (64 °F) to 23 °C (74 °F), near the comfortable range. · Low confidence
- Calm waterMostly calm3.9
Sheltered reservoir with morning starts. No chop reports, though afternoon wind is not documented. · Low confidence
- Swim easeEasy3.5
Open reservoir, but low sun made sighting hard and one 2019 racer swam toward the wrong buoy. · Low confidence
- Swim experienceGreat3.5
A fine freshwater swim with a mountain backdrop. A 2015 racer complained about a poorly set course and time-trial starts. · Low confidence
- Swim supportStandard3.4
Wave starts and standard safety. Nobody has described kayaks or ability waves. · Low confidence
Bike
Road surface, closures, scenery and wind. Counts for 18% of the overall score.
- Road surfaceGood3.5
Rural county roads. Nobody has described the surface. · Low confidence
- Road closuresPartly closed3.3
County roads with an unclear closure setup. A 2013 detour shortened the pro bike by 2 to 3 km (1.2 to 1.9 mi). · Low confidence
- Bike sceneryBeautiful4.0
Foothills, Old Stage Road and Lefthand Canyon. · Low confidence
- WindSome wind3.4
The 2007 race was windless. Wind on other years is not documented. · Low confidence
Course traits, not part of the score
- Bike speedAverage2.7
Early climb of about 183 m (600 ft), then a fast descent and rollers. The 2022 winner rode 40 km (25 mi) in 1:04:22. · Medium confidence
- Bike flatnessRolling2.7
Likely 400 to 500 m (1,300 to 1,640 ft) of climbing over 40 km (25 mi); total not published. · Low confidence
- Bike simplicitySome technical parts2.8
Steep climb, then a fast descent with a 56 km (34.8 mi)/h (35 mph) limit, plus canyon roads. · Low confidence
Run
Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.
- Crowd supportDecent3.0
Spectators lined the run in 2017, but the course is a remote dirt road at the reservoir. · Low confidence
- Aid stationsGood3.7
Aid every mile (1.6 km) with water, nutrition and ice in 2022. A 2015 racer disliked the cups. · Medium confidence
- Run sceneryPleasant3.4
Reservoir shoreline and open plains with the foothills in view. · Low confidence
- Run conditionsModerate2.8
Exposed dirt road in 32 to 37 °C (90 to 98 °F) heat at altitude. · Medium confidence
Course traits, not part of the score
- Run flatnessMostly flat3.7
Gently rolling packed dirt over 10 km (6.2 mi). · Low confidence
Conditions
Air temperature, how predictable the weather is, setting, and spectating. Counts for 13% of the overall score.
- Air temperatureWarm or cool2.5
Mornings are pleasant, but the run often tops 32 °C (90 °F); it reached 37 °C (98 °F) in 2007. · Medium confidence
- Weather reliabilityVariable3.1
Dry July weather, but the 2016 race was cancelled for wildfire and afternoon storms are possible. · Low confidence
- Venue beautyLovely3.9
Reservoir with the Flatirons and foothills behind. · Low confidence
- Spectator friendlySome viewpoints3.3
Swim and run are visible at the reservoir. The bike is far away. · Low confidence
Course traits, not part of the score
- Low altitudeHigh altitude1.3
About 1,590 m (5,215 ft) above sea level. · High confidence
Stay and travel
Hotels, walkability, getting there, and the town around the race. Counts for 10% of the overall score.
- Hotel availabilityBook early2.8
Boulder books up in July. Longmont and Denver suburbs are 20 to 40 km (12 to 25 mi) away. · Low confidence
- Hotel valuePricey2.4
Boulder lodging is pricey in summer. · Low confidence
- WalkabilityMostly driving2.4
Reservoir is 8 km (5 mi) from downtown. Park once at the venue. · Low confidence
- Travel easeEasy3.6
Denver International is about 70 km (43 mi) away. · Medium confidence
- LogisticsSome complexity3.4
One venue and one transition, but packet pickup and parking details were not found. · Low confidence
- Town and foodGreat4.5
Boulder has a deep food and cycling scene. · Medium confidence
Key facts
- Location
- Boulder, Colorado, United States
- Typical month
- July
- Latest or next date
- 12 July 2026
- Organiser
- Independent
- Field size
- About 1,500 athletes
- First held
- 1992
- Distances
- 1.5 km (0.9 mi) swim, 40 km (24.9 mi) bike, 10 km (6.2 mi) run
- Swim venue
- Boulder Reservoir (reservoir)
- Water temperature
- 18–24 °C (64–75 °F)
- Wetsuit
- Legal
- Swim start
- wave
- Bike laps
- 1
- Key climbs
- Old Stage Road, about 183 m (600 ft) in one stretch at 12 to 16 percent
- Run shade
- mostly exposed
- Air temperature
- 16–35 °C (61–95 °F)
- Humidity
- dry
- Altitude
- 1,590 m (5,220 ft)
- Nearest airport
- Denver International (DEN), 70 km (43 mi) away
- Where to stay
- North Boulder, Longmont
- Booking
- Boulder lodging is pricey in July; Longmont and Denver suburbs are cheaper 20 to 40 km (12 to 25 mi) away.
What racers and reviewers say
- Cyclizing blogRaced 2019 · blog · Positive
First-time Boulder Peak racer. Swim was clear, comfortable and wetsuit-legal, though low morning sun made sighting hard. Old Stage Road felt brutal with false summits and a 35 mph (56 km/h) limit on the descent. Run was fast and hot but manageable. Ended 8th in age group and pleased overall.
“I had my fastest Olympic distance swim and run”
- Colorado TriathleteRaced 2022 · article · Mixed
Elite-focused recap. Old Stage Road comes within minutes of the reservoir, is steep and punchy, followed by a fast descent and rolling roads back via Lefthand Canyon, Nelson Road and 63rd Street. Temperatures topped 90 °F (32 °C). Run is a packed-dirt out-and-back of about 6 mi (10 km) with aid at every mile.
“steep and punchy climb”
- Colorado TriathleteRaced 2007 · article · Mixed
Hot, dry, windless race day with 98 °F (37 °C) by 11 am. Over 1,700 starters from 31 states, sold out six months ahead. A roughly 1 mi (1.6 km) climb reaching about 16 percent on the bike. Amateurs could watch the pro race while competing.
- SlowtwitchRaced 2017 · article · Mixed
Retrospective on the Life Time years (2015 to 2016) versus the 2017 independent edition. A 2015 age-grouper called the swim course poorly set, the aid cups flimsy and the time-trial start within waves a letdown. In 2017 racers noticed lined spectators on the run and a lively, local feel. Old Stage Road is about 12 percent.
“The local flair of it wasn't there”
- SlowtwitchRaced 2013 · article · Positive
Pro-focused recap of a stacked 5i50 field. Old Stage Road adds about 600 ft (183 m) of climbing in one stretch. Construction forced a detour that shortened the bike by 2 to 3 km (1.2 to 1.9 mi). Race starts at 7:05 am at altitude.
Show 3 more
- SlowtwitchRaced 2008 · article · Mixed
Race report of an extremely hot day; winners Reed in 1:51:52 and Naeth in 2:10:07. Gives little course detail beyond confirming repeat heat risk in July.
- Finishers.comRaced 2026 · aggregator · Mixed
Listing for the 12 Jul 2026 edition and mid-July 2027. Describes Olympic triathlon, duathlon and swim-bike options, and Old Stage Road gradients near 15 percent. No reviews or totals shown.
- Colorado TriathleteRaced 2002 · article · Positive
Early-era report: over 1,200 athletes, swim temperature 74 °F (23 °C), bike climbing Olde Stage Hill and Jay Road, dirt-road run around the reservoir. Shows the Peak formula has barely changed in two decades.
Raced Boulder Peak Triathlon? Your notes on the course, conditions and logistics help the next athlete decide.
Sources
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