Ruby Lake National Wildlife Refuge lies at the southern end of the Ruby Valley in northeast Nevada. Located at an elevation of 6,000 feet and flanked on the west by the rugged and scenic Ruby Mountains, it is one of the most remote refuges in the lower 48 states. The refuge encompasses 39,928 acres and consists of a marsh bordered by meadows, grasslands, and brush-covered uplands.

It serves as a magnet for a wide diversity of wildlife species and is strategically located along migration corridors serving both the Pacific and Central Flyways. The refuge has been identified as one of 500 Globally Important Bird Areas by the American Bird Conservancy.

The National Park Service designated the South Marsh a National Natural Landmark because of the biological diversity and pristine condition of the habitat. The refuge is one of the most important waterfowl nesting areas in the Great Basin and intermountain West.

The South Marsh supports the largest population of nesting canvasback ducks west of the Mississippi River (outside Alaska), and holds the highest concentration of nesting canvasbacks in North America. Due to habitat loss elsewhere in the Great Basin, the refuge has become increasingly important to resident wildlife, including mule deer, pronghorn antelope, and sage grouse. The refuge fishery is popular with local anglers.

Located in the Great Basin of the West, Ruby Lake Refuge is a wetland oasis in Nevada's high desert. This remarkable refuge lies along the eastern flank of the scenic, snowcapped Ruby Mountains. A pristine marsh, meadows, grasslands, and shrub-steppe uplands provide essential habitat for thousands of nesting and migrating waterfowl, waterbirds, songbirds, and native wildlife.

Ruby Lake Refuge, which supports the largest population of nesting canvasback ducks west of the Mississippi River outside Alaska, is a vital waterfowl nesting area. At 6,000 feet in elevation, its 17,000-acre marsh is a remnant of a larger body of water known as Ancient Lake Franklin, which existed during the Pleistocene Epoch.

Over 160 springs emanating from the base of the Ruby Mountains provide life-sustaining water to the refuge. The marsh is surrounded by over 20,600 acres of meadows, grasslands, alkali playa, and shrub-steppe uplands.

Over 220 species of birds regularly visit the refuge. Providing nesting habitat for migratory birds is the primary purpose of the refuge, and waterfowl are the most conspicuous breeders. Canvasback and redhead ducks, among other waterfowl species, reproduce here. The once-endangered trumpeter swan, originally transplanted between 1947 and 1958 from Red Rocks Lake Refuge in Montana, is also found at Ruby Lake Refuge. Several pairs nest and raise young each year, and 40 or more birds may winter here.

In all, 15 species of waterfowl nest on this refuge, as well as a variety of other water-dependent birds such as coots, grebes, sandhill cranes, great blue herons, white-faced ibis, black-necked stilts, avocets, yellow-headed blackbirds, common yellow-throats, and marsh wrens.

Seven species of fish inhabit refuge waters. The relict dace is the only native species of fish on the refuge, and is present in only a few other basins in northeastern Nevada. A small number of Lahontan speckled dace remain from a transplant made in 1950.