US Fish & Wildlife
Management Unit: Sacramento National Wildlife Refuge Complex
752 County Road 99 W
Willows, CA 95988

The six national wildlife refuges of the Sacramento National Wildlife Refuge Complex are an island in a sea of agriculture in the Sacramento Valley of California. This valley represents the single most impotant wintering area for waterfowl along the Pacific Flyway. It represents a small portion of the vast seasonal wetlands and grasslands that once existed in the Sacramento Valley. Millions of waterfowl migrated down the Pacific Flyway to winter in the valley among resident waterbirds, deer, elk, pronghorn, and grizzly bear. With the development of agriculture, in the late 1800's and early 1900's, natural habitat was replaced with rice and other crops. Waterfowl substituted these farm crops for their original wetland foods causing serious losses for farmers.

Today, 95% of California's wetlands are gone, along with the pronghorn and grizzly bear. New wetlands can not be created naturally since levees have been constructed to confine the river for irrigation and flood control. However, the birds continue to fly their ancient routes along the Pacific Flyway, crowding into the remaining wintering habitat. The Refugees provide a significant amount of the wintering habitat for waterfowl in the Sacramento Valley.

The six Refuges of the Complex are almost entirely manmade. In 1937 with the establishment of Sacramento National Wildlife Refuge (NWR), managers and biologists worked to transform the Refuge's dry, alkaline lands into productive marshes. The Civilian Conservation Corp, using bull-dozers and tractors, began creating marshes and ponds.

Additional Refuges were created in the 1950's through the 1980's, forming the Sacramento NWR Complex. Five Refuges were created to provide wintering habitat for waterfowl and reduce crop damage. These Refuges-Sacramento, Delevan, Colusa, Sutter, and Butte Sink-consist of wetlands, grasslands, and riparian habitat along portions of the Sacramento River from Red Bluff to Princeton.

More than 300 species of birds and mammals, both resident and migratory, use the Refuges. The marshes support fish, frogs, and invertebrates, which are used by grebes, white pelicans, egrets, herons, and bitterns as a food resource. Shorebirds probe the mud for insects, snails, and worms, while raptors prey on the abundant waterfowl, rodents and small birds. woodpeckers, marsh wrens, and the finches are a few of the many song birds which feed and nest in the Refuges' cottonwoods, willows and wetland plants.

Approximately 30% of the Pacific Flyway's waterfowl population winters in the Sacramento Valley. Three million ducks, and three-quarters of a million geese migrate here.

The western pond turtle, common king snake and western fence lizard can sometimes be seen sunning themselves on logs and rocks by waterways and ponds.

Coyotes, black-tailed deer, and jackrabbits inhabit the uplands and the margins of wetlands.