Located 90 miles north of Las Vegas, the refuge contains 5,380 acres of marshes, open water, native grass meadows and cultivated croplands. It is an important stopping point for waterfowl and other migratory birds as they migrate south in the fall and back north in early spring. The diversity of the area provides habitat for a variety of birds. Waterfowl and shorebirds are most numerous during the spring and fall migrations. Great blue herons, egrets and other shorebirds can be found in the shallow areas of the marshes and lakes.
Raptors are most abundant in the summer.
Warblers, orioles and finches are abundant in the cottonwood trees that border the shorelines of the North Marsh and Upper Lake. The cultivated and open fields attract meadowlarks, blackbirds and mourning doves. Bird watching is a growing outdoor pastime that provides many hours of enjoyment in a natural environment. Over 240 different species of birds have been recorded on the refuge. Species diversity and density are highest in the spring and fall.