Point Reyes National Seashore sits on a foggy peninsula about an hour north of San Francisco. It is a place of trails, wildlife, and dramatic coastal scenery. What many visitors don’t expect to find there are dairy farms. And yet for well over a century, family ranches have been part of this landscape, some operated by the same families for five or six generations. That coexistence has been at the heart of one of the most contentious disputes in the history of the American national park...