MOJAVE, CALIFORNIA—Peter Merlin and Tony Moore explore the Mojave Desert, looking for military crash sites of experimental planes from Edwards Air Force Base. When they revisit some of these 600 crash sites, they look for small pieces of the wreckage that they research and turn over to the military. They have even recovered personal items that have been returned to family members of lost pilots. “We often approach these sites from a historical perspective. But there’s a human element that lives on. To see the emotional reaction from the family really showed me how much the sites can mean to people,” Merlin said.