Brazoria National Wildlife Refuge is five miles east of Freeport and eleven miles southeast of Angleton and is bordered to the north and east by Bastrop Bayou and to the south by Bastrop, Christmas, and Drum bays. In accord with federal migratory bird conservation acts, it provides winter habitat for migratory waterfowl. By the late 1980s the refuge comprised 12,000 acres of saline and nonsaline prairies and marshes in southern Brazoria County and offered habitat to more than 425 species of wildlife, including some 270 bird species. The refuge is dotted with numerous small lakes, including Nicks, Wolf, Salt, and Cox lakes, and is bisected by the Gulf Intracoastal Waterway and the freshwater Big Slough, which hosts a small American alligator population. The upland prairies support wildlife including sandhill cranes, coyotes, and bobcats, and the shore area hosts herons, sandpipers, avocets, and stilts. More uncommon marsh and water birds, including roseate spoonbills, double-crested cormorants, and yellow rails, make seasonal appearances, and the endangered American peregrine falcon has occasionally been seen there. Brazoria National Wildlife Refuge, along with other such refuges on the Texas Gulf Coast, provides essential winter habitat for birds on the Central Flyway, one of four major migratory routes over the continental United States. During the winter months duck and goose populations reach peaks as high as 30,000 and 40,000, respectively, and birders at the Audubon Society's December Freeport Christmas Bird Count often identify more than 200 different bird species, one of the highest counts in the country, in the vicinity of the refuge.
The refuge was established in 1966 with 6,398 acres, half of which was bought from rancher Jack Phillips. It gradually expanded with numerous smaller purchases from various landholders and in 1986 began managing the Slop Bowl addition, which it acquired from the Nature Conservancy. In the late 1980s refuge management included dikes and controlled burns and also allowed cattle grazing from October to April. In March 1991 an additional 28,655 acres, known as the Hoskins Mound Marsh, was added to the refuge, for a total of 40,854 acres. Fishing and waterfowl hunting were allowed in season. Brazoria National Wildlife Refuge is administered by the United States Fish and Wildlife Service, Department of the Interior. Its offices are based at Angleton and also serve as headquarters for the nearby San Bernard and Big Boggy National Wildlife refuges.