Cumberland Island Preservation Act

Cumberland Island Preservation Act - Adjusts the boundaries of the Cumberland Island Wilderness, Georgia, to exclude and to include certain lands if the proposed land exchange being negotiated between the Secretary of the Interior and the Nature Conservancy and High Point, Inc., is agreed to with regard to Cumberland Island National Seashore and Cumberland Island Wilderness.

Excludes the main road on Cumberland Island (as described on the register of national historic places), the spur road that provides access to Plum Orchard mansion, and such limited area on each side of these roads as necessary, from the boundaries of the Cumberland Island Wilderness and the potential wilderness area.

Requires the Secretary to: (1) restore Plum Orchard mansion at Cumberland Island National Seashore so that the condition of the restored mansion is at least equal to the condition of the mansion when it was donated to the United States; and (2) submit a comprehensive plan for the repair, stabilization, and restoration of the mansion to such condition. Authorizes appropriations.

Directs the Secretary to: (1) identify, document, and protect archaeological sites located on Federal land within the Seashore; and (2) prepare and implement a plan to preserve designated national historic sites within the Seashore.

Designates, subject to valid existing rights and pre-existing uses, a specified parcel of Federal land within Cumberland Island National Seashore as wilderness and a component of the National Wilderness Preservation System. Adjusts the boundaries of the Cumberland Island Wilderness to include the parcel.