Swim Course

Sprint 750m (0.47mi)  -  Olympic 1,500m (0.93mi)  -  Boulder Beast 1,900m

This clockwise rectangular course starts and finishes at the swim beach of the Boulder Reservoir. Kayaks, sea doos, boats, and lifeguards will be in the water to support all athletes.  If you need a rest, while in the water, waive your arms or simply swim to the nearest kayak.  You can hold on to any vessel without penalty as long as there is no forward propulsion.  If you need to cut your swim short for any reason, let the water support team member know, and they will bring you in to shore.

Aquabike Athletes: Complete the long course swim and bike. After finishing the bike, continue under the Run Start arch. Run for 0.1mi to the finish line to complete your race.



Sprint 17.3 mi  -  Olympic 26.4mi  -  Boulder Beast 50mi


Rolling hills at the base of the fabulous Flatirons! The views on this course can’t be beat!  Athletes will leave the park through the main entrance, then head south for a right on Jay Rd.  At about the 3 mile marker, you will veer right onto 28th St, then again onto N Foothills Hwy. 


Sprint Athletes: Around the 7 mile point you will come to Neva Rd where you will make a right hand turn.  After about 2 miles you will ride south & east onto Niwot Rd, then in another 2 miles you will turn right onto N 63rd St.  After approximately 1.5 miles heading south you’ll approach the aid station… just in time to turn right onto the Diagonal Hwy, hit Jay Rd again for a short stretch & head back into the park the way you came & get set to transition.

Olympic Athletes: Around the 7 mile point you will come to the intersection where Sprint athletes veer right… Olympic athletes should continue north for about 3 miles to a right hand turn onto Nelson Rd. Continue a little over 5 miles before turning right onto N 75th St.  Travel south for approximately 1.5 miles before a jog west to 73rd, then another 1.5 before a right onto Niwot and a left onto 63rd; your next right turn is onto Diagonal Hwy. Continue on Diagonal for approximately 4 miles and then turn right on Jay Road then a quick right on 51st street for your final 2.8 miles to transition!


Boulder Beast and Long Course Athletes: Complete 2 loops of the Olympic bike course. Start the second lap by going straight on Jay Road and finish the 2nd lap by turning right on 51st and returning to the Rez.


NOTE:  You will be cycling on roads that are open to traffic.  Please stay right and stay on the shoulder.  If you would need to leave the boundaries of the shoulder to pass, DO NOT PASS.



Bike Aid Stations

There will be 1 aid station on the Sprint course and 1 aid stations on the Olympic course. Please follow all staff, marshal and law enforcement directions.​




Boulder BEAST


Sprint / 5K (3.1mi) -  Olympic / 10K (6.2mi)  -  Boulder Beast / 15K 


This out and back course is flat, fast & beautiful as you run across the Boulder Reservoir dam.  Prepare for that slight downhill sprint to the finish! Boulder Beast athletes will complete the Olympic run course, turnaround and head back out to complete a second lap of the Sprint run course. 

Aid Stations

There will be aid stations approximately every mile. 5K course will have 3 opportunities to fuel up, while the 10K course will have 6 opportunities. 

The Sprint Duathlon will complete the 5K Run, 17.3mi Bike, and another 5K Run to the finish line.



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