US National Parks, National Monuments, National and International Historic Sites and Historical Parks, National Memorials, National Battlefields, Battlefield Parks, Battlefield Sites, and Military Parks, National Preserves and Reserves, National Recreation Areas, National Rivers, National Lakeshores and Seashores, Other Areas
source: http://www.infoplease.com/encyclopedia/us/national-parks-monuments-table.html
date: 04/19/2016