Chattahoochee River National Recreation Area Boundary Study Act of 2012 - Authorizes the Secretary of the Interior to study the suitability and feasibility of including approximately 45 miles of the Chattahoochee River and lands along the river corridor from the southern boundary of the Chattahoochee River National Recreation Area south to the junction of Coweta, Heard, and Carroll Counties, Georgia, within the boundary of the Recreation Area. Requires such study to include an analysis of the feasibility of administering the study area as part of the Recreation Area.