Establishes, as a unit of the National Wildlife Refuge System (System), the Cat Island National Wildlife Refuge in West Feliciana Parish, Louisiana, for the purposes of: (1) conserving, enhancing, and restoring the native bottomland community characteristics of the lower Mississippi alluvial valley, habitat to maintain and assist in the recovery of animals and plants that are endangered or threatened species, and habitats as necessary to contribute to the migratory bird population goals and habitat objectives as established through the Lower Mississippi Valley Joint Venture; (2) achieving the habitat objectives of the Lower Mississippi River Aquatic Resources Management Plan; (3) authorizing the Secretary of the Interior, acting through the Director of the U.S. Fish and Wildlife Service (Service), to assist in the restoration of forest habitat linkages between refuge land and other land to reverse past impacts associated with habitat fragmentation on wildlife and plant species; (4) providing compatible opportunities for hunting, fishing, wildlife observation and photography, and environmental education and interpretation; and (5) encouraging the use of volunteers and facilitating partnerships among the Service, local communities, conservation organizations, and other non-Federal entities to promote public awareness of the resources of the Refuge and the System (including public participation in the conservation of those resources).

Directs the Secretary to seek to acquire specified land and adjacent waters of Cat Island for inclusion in the Refuge.

Permits the Secretary to conduct projects and activities at the Refuge in accordance with this Act, including projects or activities to conserve or develop wildlife and natural resources, water supplies, water control structures, outdoor recreational activity programs, and interpretive education programs.

Authorizes appropriations.