You might want to visit this site: http://www.assateagueisland.com/ponyswim/ponyswim.htm
The pony swim was in July. When really bad storms come, I believe there is a group that heads out to the island and gets the horses rounded up to swim across to the mainland. Just like they do for the annual swim/round up.
There are wild horses on the outerbanks.
Thank you SO much! That is more and better info than I could have hoped for. Thanks especially for the link. I can’t wait to check it out!