Awesome thread idea, without the aide of the app, I tally to date:
NP (National Park)
Acadia, Bar Harbor, ME
Grand Canyon, Grand Canyon, AZ
Death Valley, Death Valley, CA
Hawaii Volcanoes, Lihue, HI
Shenandoah, Westminister, VA
North Cascades, Port Angeles, WA
Olympic, Olympic, WA
Everglades, Tamiami, FL
Great Smoky Mountains, High Point, NC
NM (National Monument)
Castle Clinton, New York, NY
Fort Pulaski, Savannah, GA
Governors Island, New York, NY
Statue of Liberty, Jersey City, NJ
Pearl Harbor, Honolulu, MI
NMe (National Memorial)
USS Arizona Memorial, Honolulu, HI
Korean War, Washington, DC
Lincoln, Washington, DC
Washington, Washington, DC
Gettysburg, Gettysburg, PA
National Seashores
Gulf Islands, LA
NHP (National Historic Park)
Chesapeake & Ohio Canal, Georgetown, DC
Independence, Philadelphia, PA
TODO: Harpers Ferry, Harpers Ferry, WV
Boston Parks, Boston, MA
Maritime, San Francisco, CA
NHS (National Historic Site)
Home of Franklin D. Roosevelt, Hyde Park, NY
La Fortaleza, San Juan, PR
NRA (National Recreation Area)
Lake Mead, NV
Gateway, Jamaica, NY
National Parkways
Blue Ridge, Asheville, NC
Baltimore Washington, Crystal City, VA
MISC
New Jersey Coastal Heritage Trail
NJ Pinelands National Reserve
National Capitol East, Washington, DC
National Mall, Washington, DC
White House, Washington, DC