4 Fore 30 Infinity Backyard Ultra

The 4 Fore 30 Infinity Backyard Ultra is an endurance running event held in Macks Creek, Missouri. Following the Big's Backyard Ultra format, runners complete a 4.1667-mile (6.7 km) loop every hour, starting at 7:00 AM, with each loop beginning precisely on the hour. Participants must finish each loop within the hour to continue, and the race continues until only one runner remains.

The course is a loop or out-and-back route, with an aid station near the start-finish line. The event supports the Kids' Harbor Child Advocacy Center, with all profits donated. Lighting is provided at the start area, and runners are advised to bring headlamps for night hours. Visit the organization's website for the most recent information.