Fat Sass Switchback Challenge

The Fat Sass Switchback Challenge is a trail running event held in Millburn, New Jersey, at the South Mountain Reservation's Locust Grove Picnic Area. Scheduled for October 5, 2025, it features a challenging 1-mile loop course with 300 feet of elevation gain, including steep climbs and technical, rocky trails. Participants can choose from a 5K race (three loops), or 3-hour and 6-hour endurance challenges, completing as many loops as possible within the time limits.

The event promotes a BYO (bring your own) approach with water and bibs provided but no swag or awards. It supports Bigger Than The Trail, a nonprofit offering free mental health therapy. Visit the organization's website for the most recent information.