The National Park Service is exploring the idea of a fence to protect ranches near Drakes Beach from the encroachment of tule elk, according to wildlife biologist David Press, who, with Marin County Park naturalist Shannon Burke, led a walking seminar in the Point Reyes National Seashore last week. Addressing the more than 50 people who attended the tour, Mr. Press also said the deaths of 255 elk between 2012 and 2014 in the fenced…