Sacramento National Wildlife Refuge Complex, National wildlife refuge complex in Glenn County, United States.

Sacramento National Wildlife Refuge Complex is a 70,000-acre (28,000-hectare) protected area with wetlands, grasslands, and riparian habitats in northern California's Sacramento Valley. The site consists of multiple sections connected by a six-mile (9.6-kilometer) auto tour route with viewing areas and walking trails.

The refuge was established in 1937 to preserve wetlands for migrating bird populations. During the Great Depression, 200 Civilian Conservation Corps workers built infrastructure including buildings, water systems, and maintenance facilities.

The refuge serves as a gathering place where visitors watch birds in their natural habitat, especially when thousands of waterfowl rest during migration seasons. People come together to experience this wildlife and learn about the importance of wetlands for protecting bird populations.

The refuge is open Thursday through Sunday, and visitors can drive or walk the six-mile auto tour route at their own pace. Coming early in the morning is best when bird activity is strongest, and bringing binoculars helps with viewing.

During winter months, visitors can see more than 500,000 ducks and 250,000 geese stopping over, as this refuge is a critical resting point on the Pacific Flyway migration route. This extraordinary concentration of waterfowl makes the colder months an incredible time to visit.