Mamba 100 - Memphis, TN
Memphis, United States • 6-7 Nov 2026
Event Overview
The Mamba 100 is an ultramarathon event taking place in Memphis, Tennessee. It features four race distances: a 100 Mile, 100K, 50K, and 25K. The event is a Western States 100 qualifier for the 100-mile distance.
Course Details
The course is based at the Wolf River Refuge Trailhead on S. Walnut Bend Rd. It consists of a primary 14-mile loop of flat, fast, and smooth singletrack trail with a few small hills. Each race distance involves completing a set number of these loops plus a short initial "lead-in" section. The start/finish area and the Walnut Grove Bridge serve as the two fully staffed aid stations.
Awards
Awards are given to the top three male and female finishers in each distance. All 100-mile finishers receive a custom buckle, with special buckles for sub-20-hour and sub-24-hour finishes. 100K finishers earn a buckle, while 50K and 25K finishers receive medals.
Participant Information
Packet pickup occurs at the start/finish line the day before the event. Participants may set up personal 10x10 canopy tents in the start/finish area. The event is a Trail Sisters Approved race. Pacers are allowed for the 100-mile and 100K distances only, and drop bags are permitted at the start/finish line. The race has specific rules regarding crew access, pacers, and conduct. The registration policy states there are no refunds or bib transfers, but entries can be deferred for race credit depending on how far in advance the request is made. Visit the organization's website for the most recent information.