Celebrating the Old Line State! Antietam, Assateague Island, Catoctin Mountain, Clara Barton, Fort McHenry, Fort Washington, Greenbelt, Hampton, Harriet Tubman Underground Railroad, Monocacy, Piscataway Park, and Thomas Stone are all above.

Appalachian Forest NHA, Appalachian Trail, Chesapeake, C&O Canal, GW Parkway, Journey Through Hallowed Ground NHA, Harpers Ferry, Potomac Heritage, Rochambeau Route, Star-Spangled Banner are all partly in Maryland, and several of these parks and trails are part of the Baltimore and Southern Maryland NHAs.