To Bone and Back Relay 2026

The To Bone and Back Relay is a 40-mile race held in Idaho Falls, Idaho, featuring staggered morning starts for solo runners and relay teams. The primary format is an out-and-back road relay, adaptable to various team sizes: eight runners can each complete 5 miles, four runners can cover 10 miles each, two runners can each do 20 miles, or a single runner can complete the entire 40 miles as an ultramarathon. The course takes runners into remote areas of Southeast Idaho, with long climbs, steep descents, and exposed sections that present a challenge beyond a typical team run. This relay has been a fixture in the region for 34 years. Its divisions include men's, women's, coed, family, and high school teams. Coed teams require a minimum of two female participants, and family teams must have members related by blood, marriage, or legal guardianship.