The Chincoteague Ponies make their way onto the shoreline after swimming across the Assateague Channel during the 90th annual Pony Swim on Chincoteague Island, Virginia, on July 29, 2015. (Brittany Greeson/The Washington Post via Getty Images)Virginia’s most famous roundup is underway at Chincoteague Island. The ponies live in two herds, one on the northern end and the other on the southern end of the island. Once they make it to Chincoteague, the ponies parade down Main Street to the carnival grounds for tomorrow’s bidding. It isn’t clear how the ponies came to live on Assateague Island, but they’ve been there since the early 1700s.