The wildlife area supports many prairie, estuary and wetland dependent species, nongame, big game and small game species of wildlife as well as native fish populations, some of which are federally endangered. Each unit provides habitat for many common species found throughout western Washington such as deer, elk, fox, bobcat, coyote, hare, raccoon, river otter, beaver, muskrat, small rodents, shrews, hawks, owls, ducks, geese, swallows, red-winged blackbird, killdeer, woodpeckers and a variety of song birds. In addition to the common species, units are managed either for recreation associated with fish and wildlife or for the protection of specific species and their habitats.