Mamba 100 - Memphis, TN

Mamba 100 - Memphis, TN

The Mamba 100 takes place November 6–7, 2026, at the Wolf River Refuge Trailhead on S. Walnut Bend Rd., Memphis, TN. The event offers multiple distances on a course built around a 14 mile loop of flat, smooth single-track with a few small hills. Runners begin with a short lead-in section before entering the main loop.

Available distances

• 100 Miler: 7 loops plus 2 mile start section, approximately 100 miles
• 100K: 4 loops plus 6 mile start section, approximately 62 miles
• 50K: 2 loops plus 3 mile start section, approximately 31 miles
• 25K: 1 loop plus 1.5 mile start section, approximately 15.5 miles

The race is a Western States qualifying event; the 100 mile distance must be completed within a 34 hour cutoff to earn WSER qualification. Two fully staffed aid stations serve the course: the Start/Finish at the Wolf River Refuge Trailhead and Walnut Grove Bridge, which runners pass twice per 14.3 mile loop. Aid stations provide water, electrolyte drink, soda, and standard ultra food. Drop bags are permitted only at the Start/Finish aid station.

Packet pickup is scheduled the day before the race at the Start/Finish trailhead, when runners may also set up approved 10x10 canopy tents for crew and personal aid. Age minimums apply by distance and pacers are allowed only for the 100 mile and 100K distances under specified rules. Awards include top three male and female finishers per distance and finisher buckles or medals for each distance. The trailhead is located just off Germantown Parkway with nearby lodging, restaurants, and services within a short drive. Visit the organization's website for the most recent information.