A bill to amend the act establishing the Big Thicket National Preserve to provide for the acquisition of property.

Provides that, effective January 1, 1976, all right, title, interest in, and right to immediate possession of the lands lcoated within the boundaries of the Big Thicket National Preserve, Texas, shall be vested in the United States. States that improved property on which residential housing is situated, the mineral estate, lands, or interests in lands owned by the State of Texas or its political subdivisions, and existing easements for public utilities, pipelines, and railroads, are exempted from these provisions.

Requires the United States to pay just compensation to the owner of any real property taken by right of eminent domain.

Authorizes the Secretary of the Interior to initiate eminent domain proceedings against improved property if, in his judgment, such lands are subject to, or threatened with, uses which are or would be detrimental to the objectives of assuring the preservation, conservation, and protection of the Big Thicket area. (Amends 16 U.S.C. 698)