Frosty Fat Sass
West Orange, United States • 31 Jan 2026
Event overview
The Frosty Fat Sass is a trail running and hiking event in West Orange, New Jersey at South Mountain Reservation. Participants can enter one of the following options:
- 5K
- 3-hour event
- 6-hour event The event is a fundraiser for the South Mountain Conservancy; funds raised support preservation and education programs. The event is self-supported: there are no aid stations or finishers' swag, and refunds or deferrals are not offered.
Course and logistics
The standard loop is a 5K that starts and finishes at the Turtleback Rock Picnic Area off Walker Road. The loop includes about 289 ft of elevation gain and combines wide dirt or gravel carriage roads with technical singletrack that has rocks and roots. Specific features noted: a 1/2 mile, 200+ ft rocky descent near mile one, a 100 ft climb around mile 2.5, and a rocky singletrack last mile. Portapottys are available at the start/finish area. The course will be marked with bright ribbons at turns; participants must record loops on the loop board to be included in final results.
Divisions and participant rules
There is a Rucking Division within the 3-hour event with two weight classes: 15 lb (lightweight) and 30 lb (heavyweight). Weight must be carried in a pack or ruck; weight vests are not allowed and listed weight is the pack dry weight. Participants over age 60 and athletes with disabilities may use a pacer or guide; pacers for other participants require prior approval. Kids under 19 have a youth discount and the event includes family-friendly activities. Visit the organization's website for the most recent information.