The Indian Health Service was an unlikely place for Emily Hartzog to land after specialty medical training in New York City, but caring for the quiet, unfathomable Navajo in Shiprock, New Mexico became the focus of her life. She and her husband moved to the Four Corners region, named because it takes in parts of four states-Colorado, Utah, Arizona, and New Mexico, and, with no farming background, bought a beautiful property on a rough canyon road. Dr. Hartzog's Southern upbringing hadn't prepared her well for herding cattle, delivering sheep, or planting a vineyard in a place of harsh...