Furbutt After Dark 12-Hour Ultra

The 12-hour Furbutt After Dark ultra uses a backyard format: one hour to complete each 4.167-mile loop. You must be in the corral ready to start the next loop on the hour, or you're out. Runners who quit voluntarily or miss a lap start are eliminated. The last runner standing must complete their final lap solo. This challenging run is excellent for experiencing the backyard format and pushing for a marathon, 50K, or 50-mile distance, as it forces early, frequent rest.