Colorado Triathlon
Boulder, USA · June · Independent (Without Limits Productions, USA Triathlon sanctioned)
Course: 0.8 km (0.5 mi) swim, 27.4 km (17.0 mi) bike, 5 km (3.1 mi) run. 750 m (0.47 mi) swim / 17 mi (27.4 km) bike / 3.1 mi (5 km) run
Why people love it
- Sprint is 750 m (0.47 mi), 27.4 km (17 mi), 5 km (3.1 mi); first-timer wave capped at 50.
- Flat, fast dirt-road run and a bike loop with mountain views.
- Limited to 700 athletes; the organiser says it has sold out every year from 2010 to 2025.
- Race-morning packet pickup is possible for $10, plus pre-race pickup in Westminster and Boulder.
Watch out for
- Boulder Reservoir is at about 1,590 m (5,220 ft); expect to run slower than at sea level.
- Water is in the mid 60s °F (about 18 °C (64 °F)) in early June; a 2019 racer called it breath-taking cold.
- The Olympic bike is 37.8 km (23.5 mi), short of the standard 40 km (24.9 mi).
- Transition racks filled early in 2019 and some racers took extra space; arrive early.
- Only two blog reports exist, from 2016 and 2019. No refunds for any reason.
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: Moderate
- Racer satisfactionLoved3.8
Two blog reports from 2016 and 2019: one happy and surprised by the clean reservoir, the other mixed on the bike and transition space. · Low confidence
- OrganizationWell run3.9
2016 racer praised guided parking, early transition opening and free beer; 2019 racer felt others hogged rack space. · Low confidence
- First timer friendlyFriendly4.3
Capped first-timer wave and a 27.4 km (17 mi) bike. · Medium confidence
Course traits, not part of the score
- PR potentialAverage3.4
Fast run; rolling bike and altitude. · Low confidence
Swim
Wetsuit odds, water temperature, calm, and the experience of the start. Counts for 16% of the overall score.
- Wetsuit legalAlmost always4.5
Water in the 60s °F (about 18 °C (64 °F)) in June means wetsuits are normal; both racers wore them. · Low confidence
- Water temperatureAcceptable3.0
68 °F (20 °C) in 2016 but a racer in 2019 called the water breath-taking cold. · Medium confidence
- Calm waterMostly calm3.7
Reservoir swim with no chop complaints; the 2016 racer called it calm and clean. · Low confidence
- Swim easeEasy3.9
750 m (0.47 mi) in cold reservoir water. · Low confidence
- Swim experienceGreat3.6
Murky but cleaner than the 2016 racer expected. · Low confidence
- Swim supportGood3.9
A capped first-timer wave helps; other support is not described. · Low confidence
Bike
Road surface, closures, scenery and wind. Counts for 18% of the overall score.
- Road surfaceGood3.6
Surface is not discussed by athletes. · Low confidence
- Road closuresPartly closed3.2
Roads are open with traffic control; one racer found it uncongested. · Low confidence
- Bike sceneryBeautiful3.9
Mountain views on the bike loop. · Low confidence
- WindMostly calm3.8
The 2016 racer found the bike calm. · Low confidence
Course traits, not part of the score
- Bike speedFast3.6
Uncongested after the start; one climb. · Low confidence
- Bike flatnessRolling3.4
Rollers and the Jay Road climb over 27.4 km (17 mi). · Low confidence
- Bike simplicityMostly simple3.7
Single loop north of the reservoir; no navigation complaints. · Low confidence
Run
Crowds, aid stations, conditions underfoot and scenery. Counts for 13% of the overall score.
- Crowd supportDecent3.0
Reservoir venue with free beer at the finish; crowd comments are scarce. · Low confidence
- Aid stationsGood3.5
Aid is not described by either racer. · Low confidence
- Run sceneryBeautiful3.7
Reservoir run with mountain views. · Low confidence
- Run conditionsEasy3.9
Flat but at altitude. · Low confidence
Course traits, not part of the score
- Run flatnessFlat4.7
Flat dirt-road run. · Low confidence
Conditions
Air temperature, how predictable the weather is, setting, and spectating. Counts for 13% of the overall score.
- Air temperaturePleasant4.2
Early June at altitude means cool mornings. · Medium confidence
- Weather reliabilityVariable3.4
The organiser can change the course for weather; no athlete reports on it. · Low confidence
- Venue beautyLovely3.9
Reservoir with mountain views and a clean look. · Low confidence
- Spectator friendlyEasy3.5
Reservoir venue; spectator comments are scarce. · Low confidence
Course traits, not part of the score
- Low altitudeHigh altitude1.2
Boulder Reservoir is at about 1,590 m (5,220 ft). · High confidence
Stay and travel
Hotels, walkability, getting there, and the town around the race. Counts for 10% of the overall score.
- Hotel availabilityGood3.8
Boulder has many hotels; athletes say little. · Low confidence
- Hotel valueNormal2.7
Boulder lodging is expensive; no athlete comments. · Low confidence
- WalkabilitySome driving3.4
Parking is volunteer-guided; transition is a short walk, but the 2019 racer found racks filled early. · Low confidence
- Travel easeEasy3.7
Denver airport is about an hour away; one racer drove an hour from Parker. · Low confidence
- LogisticsSimple4.0
Race-morning packet pickup is possible for $10 and transition opens at 6 am, but racks filled early in 2019. · Medium confidence
- Town and foodGood4.3
Boulder has a strong restaurant scene. · Low confidence
Key facts
- Location
- Boulder, Colorado, USA
- Typical month
- June
- Latest or next date
- 5 June 2027
- Organiser
- Independent (Without Limits Productions, USA Triathlon sanctioned)
- Field size
- About 700 athletes
- Entry fee
- About $125
- Distances (non-standard)
- 0.8 km (0.5 mi) swim, 27.4 km (17.0 mi) bike, 5 km (3.1 mi) run
- Cutoffs
- Swim 9:00 am, Bike 10:45 am
- Swim venue
- Boulder Reservoir (rectangular course, counter-clockwise, exit at south end of the beach) (reservoir)
- Water temperature
- 16–20 °C (61–68 °F)
- Wetsuit
- Legal
- Swim start
- wave, a new wave about every 5 minutes; first-timer wave goes last in the sprint, capped at 50
- Swim laps
- 1
- Bike laps
- 1
- Key climbs
- Jay Road climb
- Run laps
- 1
- Air temperature
- 10–27 °C (50–81 °F)
- Humidity
- Low
- Altitude
- 1,590 m (5,220 ft)
- Nearest airport
- Denver International (DEN), 65 km (40 mi) away
- Where to stay
- Boulder, Longmont
- Booking
- Boulder hotels are pricey; many racers drive in from Denver, Longmont or Colorado Springs.
What racers and reviewers say
- Cyclizing (blog)Raced 2016 · blog · Positive
A racer on his third triathlon found the reservoir cleaner than expected and the event well run: transition opened at 6 am, volunteers guided parking, the first sprint wave started after the Olympic waves, and free beer waited at the finish. Water was said to be 68 °F (20 °C), murky but clean; he wore a wetsuit and lost time removing it in sand. Bike was calm and uncongested after the start; he finished 7th in his division.
“Boulder Reservoir was nice, I was surprised how clean it was.”
- Cyclizing (blog) 2019 reportRaced 2019 · blog · Mixed
Mid-pack sprint racer from Parker, about an hour away, who left at 5:30 am. Cold water took his breath away but the swim went well; bike was his weak leg, with the climb up Jay Road a trouble spot. Transition filled early and he felt others hogged rack space. Run was decent until fading near mile 2 (3.2 km).
Raced Colorado Triathlon? Your notes on the course, conditions and logistics help the next athlete decide.
Sources
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