Mammoth TUFF is an annual gravel cycling event held in Mammoth Lakes, CA, organized by TUFF Ventures (David Sheek and Amanda Nauman). The event offers three ride distances — ranging from roughly 40 to 100 miles — through the Long Valley Caldera and Volcanic Tableland of the Eastern Sierra. The name references the volcanic tuff stone that defines the local gravel terrain. The multi-day weekend includes a Friday beer mile and group rides, Saturday’s main ride starting near The Village at Mammoth, and a Sunday awards ceremony. Certain categories qualify riders for the UCI Gravel World Championships. Ten percent of entry fees are donated back to public lands.