Frosty Fat Sass
West Orange, United States • 31 Jan 2026
The Frosty Fat Sass is an annual trail running and hiking event held at South Mountain Reservation in West Orange, New Jersey. Participants can choose from a 5K loop, a 3-hour, or a 6-hour endurance challenge, with a new rucking division available for the 3-hour event. The course features a mix of wide carriage roads and technical singletrack trails with rocks and roots, offering 289 feet of elevation gain.
This self-supported "fat-ass" event emphasizes fun and community, with no aid stations or finishers' swag. Proceeds benefit the South Mountain Conservancy, supporting local trail preservation and education. The event welcomes all ages and abilities, including family-friendly activities and discounts. Visit the organization's website for the most recent information.