A heavily clouded sky hangs above loblollies and the silver water of the Assateague Channel. This shallow, tidal salt marsh tucked between Chincoteague Island and the long tail of Assateague Island is the location of the annual Pony Swim made famous in Marguerite Henry’s Misty of Chincoteague. Barrier islands like Chincoteague, along the ocean side of the Eastern Shore of Maryland and Virginia, are rich environmental landscapes, constantly changing because of shifting sediments, wave action, and erosion.