Jeffery Goldstein, fish biologist and park dive officer for Death Valley National Park, right, descends into Devils Hole for a biannual count of the Devils Hole pupfish at Devils Hole in the Ash M …

Jeffery Goldstein, fish biologist and park dive officer for Death Valley National Park, right, descends into Devils Hole for a biannual count of the Devils Hole pupfish at Devils Hole in the Ash Meadows National Wildlife Refuge on Saturday, April 7, 2018. Patrick Connolly Las Vegas Review-Journal @PConnPie