The Southern Nevada fish thought to be the world’s most endangered has made a stunning rebound. During a fall count in Death Valley National Park’s Devils Hole, next to the Ash Meadows National Wildlife Refuge, biologists counted 137 Devils Hole pupfish, up from 77 last spring and 69 last fall. … The Devils Hole pupfish earned its endangered listing under the federal Endangered Species Act in 1967 in response to the major threat of groundwater drawdown from ranching and agriculture. The U.S. Supreme Court intervened, too. In its decision on 1976 Cappaert v. United States, the court upheld the ruling that ranchers could not pump groundwater in a way that would affect levels at Devils Hole and undermine the federal government’s mission of conservation at what was then a national monument.