Advocates characterize Sheldon as one of the few intact
sagebrush steppe ecosystems in the
Great Basin, one that hosts a variety of wildlife endemic to the unique environment. The Sheldon National Wildlife Refuge occupies an arid zone of volcanic terrain. The elevation ranges from to above sea level.
Geothermal hot springs provide some water to a swimming pool and shower house in the campground.
Flora and fauna The dominant plant life consists of drought-tolerant species such as
sagebrush,
juniper,
mountain mahogany,
bitterbrush, and
aspen. In this forbidding landscape lives a large population of free-range
fauna. Desert fishes,
greater sage-grouse, migratory birds,
mule deer, and the
pygmy rabbit are all residents, with the
pronghorn – North America's fastest land mammal – being the best known and numbering around 3,500. There are also large herds of
mule deer, and a small but self-sustaining population of
bighorn sheep. The
bighorn is not strictly native to the Sheldon Refuge, having been extirpated there during the frontier era and re-introduced about 1930. The
pronghorn played a key role in the refuge's history, as approximately 94 percent of the current protected land area was originally set aside as the
Charles Sheldon Antelope Range in 1936. The refuge is the home of the
Alvord chub, an
endemic fish species of limited geographic distribution. Formerly the wildlife reserve hosted
mustang, feral horses, but by 2014 these had all been removed (see below).
Minerals Opal miners have been active in the valley since 1906. The refuge contains the very active and popular Virgin Valley Opal Mining District whose mineral rights were grandfathered-in with the establishment of the sanctuary. Rockhounds search for
precious opal,
agates,
petrified wood,
carnelian,
obsidian,
rhyolite,
jasper,
hyalite opal, and
psilomelane, among other semiprecious
gemstones. The Virgin Valley Mining District is known for
black opals, the
Nevada State Gemstone, still very active with multiple fee-dig mines. ==Climate==