FLAGSTAFF, AZ—After more than three days of hiking, canoeing and other outdoor activities, a naturist/nudist outing concluded yesterday with a large boner. "By the time the retreat had ended, there were lots of tired people, worn out from a long weekend of fun but strenuous activity," said Dale Pursner, tour leader for the Southern Exposure Naturist Getaways outing. "There also were a lot of stiffies."