Sutter National Wildlife Refuge, Wildlife refuge in Sutter County, United States.

The Sutter National Wildlife Refuge is a protected area in Sutter County containing wetlands, riparian corridors, and grasslands spread across the Sacramento Valley. The site spans over 2,500 acres and links different habitats that support vast numbers of migratory birds.

The refuge was established in 1945 by the U.S. Fish and Wildlife Service as part of a broader conservation network in the Sacramento Valley. It grew from the need to protect bird populations and preserve wetlands for future generations.

The refuge's mixed riparian forest shelters a large heron and egret rookery, and the wetlands draw wintering flocks of more than 175,000 ducks and 50,000 geese. Birders time visits to these seasonal gatherings, watching waterfowl and wading birds from the trails and viewing platforms.

About 80 percent of the refuge lies within the Sutter Bypass, which floods at least once a year and can submerge parts of the site under up to 12 feet (3.7 m) of water, so check conditions before setting out. The refuge sits roughly 50 miles (80 km) north of Sacramento, near Yuba City, and is reached by road through surrounding farmland.

The area floods annually through the Sutter Bypass, temporarily creating massive feeding grounds for migrating ducks and geese passing through the region. These inundations are unpredictable and turn parts of the refuge into shallow lakes for weeks at a time.