When David and Courtney Reeder Jones moved into two rooms reached by ladder in a northern Arizona Indian ruin, they had been married only two weeks. Except for the ruin's cement floors, which were originally hardened mud, and skylights instead of smokeholes, the rooms were exactly as they had been 800 years before. The year was 1938, and the newlyweds had come to Wupatki National Monument as full-time National Park Service caretakers for the ruin...