The 3,750-acre Clarence Cannon National Wildlife Refuge is located in the floodplain of the Mississippi River, adjacent to Pool No. 25. The refuge's diversity of habitats supports waterfowl, wading birds, shorebirds, and songbirds. Although it is protected by a levee, the refuge provides flood storage in periods of high water.

Clarence Cannon Refuge is managed by Great River National Wildlife Refuge, which is part of the Mark Twain National Wildlife Refuge Complex.

From St. Louis, take I-70 west to the Highway 79 exit. Take Highway 79 north approximately 35 miles to the town of Annada. In Annada, take County Road 206 east one mile to the refuge office.