S.3449: A bill to direct the Secretary of the Interior to study the suitability and feasibility of designating sites in the Lower Mississippi River Area in the State of Louisiana as a unit of the National Park System, and for other purposes.

Lower Mississippi River National Historic Site Act of 2008 - Directs the Secretary of the Interior, through the Director of the National Park Service (NPS), to complete a special resource study that evaluates the national significance of the Lower Mississippi River area in Louisiana and the suitability and feasibility of designating such area as a unit of the National Park System, which shall be known as the "Lower Mississippi River National Park."