Sheldon National Wildlife Refuge, national wildlife refuge in Humboldt County, Nevada, United States

Sheldon National Wildlife Refuge is a nature reserve spanning volcanic terrain with elevations between 4,100 and 7,200 feet across the Nevada-Oregon border. The landscape consists mainly of sagebrush steppe ecosystems typical of the Great Basin.

The refuge was created by executive order in 1931 to protect declining pronghorn, conserve native fish, wildlife and plants, and serve as an inviolate migratory bird sanctuary. In 1936 about 94 percent of today's protected area was set aside as the Charles Sheldon Antelope Range. The Virgin Valley Opal Mining District, active since 1906, kept its mineral rights when the refuge was established.

The Virgin Valley opal fields have drawn miners since 1906, and the mining district's rights were grandfathered in when the refuge was created. Rockhounds still search the valley for black opal, the Nevada state gemstone, along with agates, petrified wood, carnelian, obsidian and jasper at fee-dig mines.

Nevada State Route 140 is the only paved road through the refuge, crossing it east to west. The nearest community of any size is Denio, Nevada, 14 miles from the eastern boundary; the nearest divided highway is Interstate 80 at Winnemucca, about 100 miles south. A campground has a swimming pool and shower house fed by geothermal hot springs.

Opal miners have worked Virgin Valley since 1906, and the district's mineral rights were grandfathered in when the refuge was created. The Nevada state gemstone, black opal, is still found here at fee-dig mines, alongside agate, carnelian and petrified wood. A point inside the refuge lies 115 miles from the nearest McDonald's, the farthest spot in the contiguous US.