"This is all in good fun, but it's not a joke, " says Mr. Olsen, a lawyer in Tahoe City, Calif.

WSJ: Hair-Raising Competition Splits the Mustache World

Campgrounds line the lake and everything from rustic cabins to four-star hotels can be found in areas like Nevada's Stateline and the California side's Camp Richardson and Tahoe City.

BBC: Lost in paradise