[7] While this process has benefitted Ocean City, creating wider beaches and better fishing access,[9] it caused erosion problems on Assateague.

[7] Between 1933 and the early 1960s, U.S. federal government interest in creating a national seashore on the island alternated with periodic pushes for development.

The national seashore was established in 1965 to preserve the barrier island and surrounding waters, and provide recreational opportunities.

All of the island south of the state border in Virginia is the Chincoteague National Wildlife Refuge, with the exception of a one-mile stretch of land including the recreational beach and interpretive facilities managed by the NPS.

[12] The U.S. Geological Survey has initiated studies aimed at mitigating the potential sea-level rise on this barrier island complex.

The island has a land area of 24.4 square miles (63 km2) and has no resident population in either Maryland or Virginia, though a few retained property rights until 2006.

Large populations of birds inhabit the island, including American oystercatcher, great blue heron, and snowy egret.

The traditional definition of a horse or a pony is based on whether the animal in question falls over or under 14.2 hands (58 inches, 147 cm).

[21] When excess numbers are removed from the island and they are placed into human ownership, they adapt quickly to domestication.

Made famous by Marguerite Henry in her children's book Misty of Chincoteague, the animals are popular tourist attractions and subjects for photography.

Once a year in July, the local "salt water cowboys" round them up and sort a number of animals to be removed from the island, which are put up for auction on Pony Penning Day.

[23] In Virginia, the Pony Penning Days auction keeps the horse population at levels required by agreement with the Chincoteague National Wildlife Refuge.