Bad Ass Backyard Ultra - Rio Linda, CA

The Bad Ass Backyard Ultra (B.A.B.U.) is a challenging endurance running event held at Dry Creek Parkway in Rio Linda, California, near Sacramento. Participants run a 4.16-mile loop every hour, starting on the hour, and must be ready to begin each new loop on time or face elimination. The race continues until only one runner remains, completing the most loops.

Originally launched in 2023 as a fatass event, B.A.B.U. became an official backyard ultra in 2024 through a partnership between Skybreaker Racing and Auburn Area Trail Runners, now under Singletrack Running. It is affiliated with the national and world backyard ultra championships, offering competitors a chance to qualify for international events. Visit the organization's website for the most recent information.