A bill to amend the Act establishing the Indiana Dunes National Lakeshore to provide for the expansion of the lakeshore and to increase the number of members on the advisory commission for the lakeshore.

Amends the Act establishing the Indiana Dunes National Lakeshore to expand the boundaries of the lakeshore.

Increases the number of members of the Indiana Dunes National Lakeshore Advisory Commission from 11 to 13. Increases the number of members of such commission who are to be year-round residents of Gary, Indiana, from one to two.

Directs the Secretary of the Interior to construct or enter into a cooperative agreement with Indiana for the construction of a marina with harbor facilities within a specified area.

Allows the Secretary to acquire only so much of an interest in a specified property as is necessary to assure public access.

Allows the use of funds appropriated for the purposes of establishing the Indiana Dunes National Lakeshore for acquisition of the additional property authorized by this Act.