Assateague Island National Seashore

Wild horses graze the dunes and salt marshes of Assateague Island, a 37-mile (60 km) barrier island that is never more than a mile wide. Legend says they swam ashore from a wrecked Spanish galleon. The Park Service holds the likelier view that 17th-century mainland farmers let them loose to avoid fencing laws and taxes, though a 2022 DNA study found Spanish ancestry in the herd. A fence at the state line divides two herds. On the Maryland side the horses are managed as wildlife, kept to about 80 to 100 animals with a dart-delivered contraceptive.

On the Virginia side, the Chincoteague Volunteer Fire Company owns about 150 ponies that graze within Chincoteague National Wildlife Refuge. Each July, during Pony Penning, 'saltwater cowboys' swim them across the channel to Chincoteague Island and auction some of the foals, a swim held since 1925 that Marguerite Henry made famous in her 1947 book Misty of Chincoteague. The island might have become a resort instead. Developers had laid out lots and roads when the Ash Wednesday Storm of 1962 swept them away, and Congress established the seashore in 1965. It covers about 41,300 acres (167 km²) of land and water.

• Maryland
  The Old Line State, wrapped around Chesapeake Bay located in
• The Mid-Atlantic
  The dense middle of the eastern seaboard, New York to Washington located in
• Virginia
  The Old Dominion, from the Chesapeake to the Blue Ridge located in
• Chesapeake Bay
  The largest estuary in the United States near
• Cape Hatteras National Seashore
  The first national seashore, on North Carolina's eroding Outer Banks related