When it comes to surviving the apocalypse, you could do a lot worse than the West Virginia branch of Fortitude Ranch, a constellation of five survivalist compounds across the United States and one of a growing number of businesses aiming to seize on Americans’ deepening anxieties about the future.

Set on a rise above the lush valley cradling the Lost River in eastern West Virginia, about two hours from Washington, D.C., the 50-acre property backs up against the George Washington and Jefferson National Forests. A handsome guesthouse, built of dark timber slats, anchors the property. Two large, boxy dormitories, also timber but more rustic, as well as a bare-bones bunker, are designed to house more than 100 members. They are each…