Co-created by champion gravel cyclist and Mammoth Lakes resident Amanda Nauman, Mammoth TUFF gets its name from the volcanic rocks (aka “tuff”) that comprise the gravel terrain in the area. Also, the riding is downright tough. You can choose the degree of difficulty, though, with the two ride options: a 45-miler circling a caldera with 2,000 feet of climbing, or the 100-mile route with 8,000 feet of elevation gain. The long course travels through the Volcanic Tableland formed by the Long Valley Caldera. Post-ride, there's plenty to explore in the Mammoth Lakes area—take a dip in the local hot springs, sip a microbrew from Mammoth Brewing, and hit up the local bike park. mammothtuff.com