Colusa National Wildlife Refuge is one of six refuges in the Sacramento Refuge Complex located in the Sacramento Valley of north-central California. The refuge is about 70 miles north of the metropolitan area of Sacramento.

The 4,507-acre refuge primarily consists of intensively managed wetland impoundments, with some grassland and riparian habitat. The Sacramento Valley is one of the most important wintering areas for waterfowl in North America. Colusa Refuge typically supports wintering populations of more than 200,000 ducks and 50,000 geese.

Wetland impoundments are intensively managed to provide optimal habitat for the dense concentration of wintering waterfowl, as well as habitat for resident wildlife and spring/summer migrants.

The grassland habitat supports several populations of endangered and sensitive species of plants. The refuge is a stronghold for populations of the endangered palmate-bracted bird's-beak and the threatened giant garter snake. About 35,000 visitors come to the refuge each year for wildlife viewing and 4,000 come to hunt waterfowl and pheasant.

For the wildlife viewing area: from Colusa, drive one-half mile west on Highway 20 to the Refuge entrance.

From Williams, exit Interstate 5 on exit 578 for Highway 20 Clear Lake/Colusa turn east. Travel approximately six miles on Highway 20 to graveled Ohair Road.