Results/Photos

Date: Sept. 27, 2026 Participant: Annie O'Brien #13366 Race: 2026 Boulderthon Marathon Distance: 26.2 miles

Even Effort Through 20 Miles Fuels Steady Marathon Finish Annie O'Brien completed the 2026 Boulderthon Marathon in 4:03:16, an average pace of 9:17 per mile. She opened conservatively at 9:20 for the first mile, then settled into a tight band between 8:50 and 9:10 per mile through the middle of the race, holding that rhythm from mile 4 to mile 19. Her strongest mile-plus stretch came from mile 9 to mile 11, where she clicked off consecutive splits of 8:53, 9:02, and 8:31 her fastest mile of the day. Pace eased over the closing miles, with mile 21 to 23 slipping into the 9:5510:30 range before tightening again to 9:22 over the final mile to the Pearl Street Mall finish. The marathon's second half winds past Boulder Reservoir before returning to downtown Boulder, and O'Brien passed the lululemon Power-Up Zone near mile 22.5 during her toughest patch of the race, just before regaining footing for the stretch to the finish at over 5,000 feet of elevation.