Crystal Stillwell, Bernard Beckwith and Christian Simpson are pleading innocent to charges of indecent conduct.
The Black Frog Restaurant on Moosehead Lake has a standing offer of a free prime rib sandwich to skinny-dipping customers.
Authorities say no one in the restaurant objected to the naked trio.
But the three were charged after a family on a nearby boardwalk complained to police.
Their trials are set for November 3rd.
