There are few places in the United States where you can view wild horses in their natural habitat. If you visit Assateague Island in Worcester County, you will encounter the feral descendants of once tame horses. The horses are split into two main herds, one on the Virginia side and one on the Maryland side of Assateague. They are separated by a fence at the Virginia/Maryland State line.
There are a couple of theories as to how the nearly 300 horses arrived off the coast of MD/VA. Some believe a Spanish ship sank offshore forcing a cargo of horses to swim ashore in the 1600s, while others say early colonial settlers brought the horses to the island to graze and avoid fencing laws and livestock taxation.
Regardless of their origin, the National Park Service (which manages the Maryland herd) cautions visitors to view the horses at a distance and give the horses the space they need to be wild.