Tartarus Backyard Ultra
Spokane, United States • 15 Aug 2026
Event Details
The Tartarus Backyard Ultra is a "last person standing" endurance event. It features two separate concurrent races: a run event and a ruck event. Participants may only enter one of the two races.
Course and Format
The race begins at 8:00 AM. Runners complete a loop of 4.1667 miles, while ruckers complete a loop of 2.2 miles. Each participant has exactly one hour to finish their loop and return to the starting corral. A new loop starts every hour on the hour. If a participant is not in the starting corral when the bell rings to begin the next loop, they are eliminated. The race continues in this format until only one runner and one rucker remain. Those final participants must complete one more loop alone to be declared the winner; all others receive a DNF (Did Not Finish).
The course changes at 8:00 PM, moving to an out-and-back route on the Centennial Trail. It returns to the original trail loop at 8:00 AM the following morning.
Logistics and Rules
The event is held at Camp 7 in Riverside State Park, Spokane, Washington. Participants must provide their own aid; crews are permitted but not required. A small personal gear area is available near the start/finish. Camping is permitted nearby. Portable toilets are located near the start line. Once the bell rings to start a loop, participants may not receive aid from crews or visit their gear, except to use the portable toilets.
Special Category: Backyard 24
A separate "Backyard 24" category is offered. In this format, all participants who complete 24 hours are tied for first place. This is presented as an introduction to the backyard ultra format.
Ruck Event Specifications
Ruck participants must carry a traditional rucksack (no vests allowed) with a required core weight. The core weight is 30 pounds for individuals weighing over 150 pounds, and 20 pounds for those weighing 150 pounds or less. This weight does not include consumables like water or food.
Registration Alternative
Participants have the option to fundraise a minimum of $100 for the organizer's cause instead of paying a registration fee. Visit the organization's website for the most recent information.