To ratify a memorandum of agreement concerning the cooperative management of public lands included within the National Wildlife Refuge System on Matagorda Island, Texas, and for other purposes.

Ratifies an exchange agreement providing for management of National Wildlife Refuge System lands and State lands on Matagorda Island, Texas.

Amends the National Wildlife Refuge System Administration Act of 1966 with respect to the disposal, management, and acquisition of lands and interests in lands included in the System.

Requires the Director of the United States Fish and Wildlife Service to request the National Academy of Sciences (NAS) to develop a protocol for an experimental four-year study of and report on the effects of cattle grazing on Matagorda Island, Texas. Allows the Director, based on such report, to extend the term of the existing cattle grazing permit on the Island, unless continued grazing on it would be incompatible with the primary purposes for the establishment of the original Matagorda Island National Wildlife Refuge.