A bill to amend the Act establishing the Indiana Dunes National Lakeshore to provide for the expansion of the Lakeshore, to increase the number of members on the advisory commission for the Lakeshore, and to authorize the appropriation of funds for the construction of a marina within the Lakeshore.

Expands the boundaries of the Indiana Dunes National Lakeshore. Increases the number of members on the Indiana Dunes National Lakeshore Advisory Commission from 11 to 13 members.

Prohibits the Secretary of the Interior from acquiring, after January 1, 1986, any property within a specified lakeshore area if construction begins on an energy transmission or storage substation within such area.

Authorizes an appropriation of $25,000,000 for the construction of a marina within the lakeshore.