Bonneville Backyard Ultra

APR
25
2026
Test your limits at the Bonneville Backyard Ultra near Deer Creek Reservoir where runners complete a 4.167 mile loop each hour until only one remains. Smooth, runnable terrain and an hourly restart make this a fierce mental challenge.
Sat 25 Apr 2026
4.167-Mile Loop Every Hou...

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Format and rules

The Bonneville Backyard Ultra is a last-person-standing event using the Backyard Ultra format. Runners must complete one 4.167-mile loop every hour. The race continues until only one runner remains; all other participants receive a DNF when they fail to start a loop on time. No late starts and no pacers are allowed. Organizers mark a corral around the start area to track which runners are continuing each hour.

Race signals are used to mark the countdown each loop: 3 whistles = 3 minutes to go, 2 whistles = 2 minutes to go, 1 whistle = 1 minute to go, and the bell = GO on the hour.

Course and logistics

The course is an out-and-back along Deer Creek Reservoir near the Deer Creek Dam Trailhead in Provo, UT, with about 2.08 miles each way. The terrain is described as mostly smooth and very runnable. Organizers note that repetition, the mental game, sleep deprivation, and the hourly restart are factors that affect participants. The event may invite a small number of waitlisted runners as standby participants on race day; such invitations are not guaranteed entries. Registration closes on Mon, Apr 27 at 11:59 PM MT. Visit the organization's website for the most recent information.

4 mi
4.167-Mile Loop Every Hour

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