Utah’s Original Backyard Ultra!
The Bonneville Backyard Ultramarathon is a true last person standing race. Based on the original Backyard Ultra format created by Lazarus Lake, the rules are simple—but finishing is anything but.
You must complete one 4.167-mile loop every hour on the hour. Finish a loop early? Great—rest, refuel, stretch, panic, question your life choices—just be back in the corral before the next bell rings. The moment you fail to start a loop on time, you’re out. No late starts. No pacers. No exceptions. Only one runner will finish. Everyone else will DNF. That’s the beauty of it.
Our course is an out-and-back along the scenic Deer Creek Reservoir, with about 2.08 miles each way. The terrain is mostly smooth and very runnable—but don’t be fooled. The repetition, the mental game, the sleep deprivation, and the hourly restart will wear on even the toughest runners.
The race begins at 9:00 AM on April 26, 2025. All runners must be at the start line by 8:55 AM so we can paint a corral around you—this corral is how we track who is continuing each hour. Every loop, you’ll hear our signals:
3 whistles = 3 minutes to go
2 whistles = 2 minutes to go
1 whistle = 1 minute to go
The bell = GO (exactly on the hour, every hour)
If you’re not inside the corral when the bell rings, you’re done. Congrats on your DNF—it’s nothing to be ashamed of. Everyone except one of you will get one.
Some show up to win. Most show up to find out what they’re made of. Whether your goal is 4 loops or 40, this event is about going further than you thought possible. There’s no finish line. There’s no time limit. Just you, the bell, and the next loop.
Important Note:
Due to occasional last-minute no-shows, we reserve the right to privately invite a small number of waitlisted runners to be present on race day as standby participants. These invitations are not guaranteed entries, but help ensure the race reaches its full competitive potential.
For all the nitty-gritty details (gear, rules, parking, crew info, etc.), head to:
www.bonnevillebackyardultra.com
Still have questions? Reach out anytime—we're here to help.
And if you're ready to toe the line, we’ll see you in the corral.
Event's current local time: 9:59 AM MT
