If you think you might want to visit more than one of the Corps of Engineers parks this year, it might be a good idea to invest in an Annual Day-Use Pass. For $30, you get a tag to display by hanging from your rear-view mirror that gets your visitor or day-use fee waived. You can purchase a Day-Use Pass at the welcome center of any Corps of Engineers park.
http://www.saw.usace.army.mil/Locations/DistrictLakesandDams/JohnHKerr/Recreation/Passes.aspx