Gulf Islands National Seashore stretches along the Gulf of Mexico in Florida and Mississippi, preserving barrier islands, mainland shorelines, historic military sites, and extensive underwater acreage. Authorized in 1971, it protects a coast formed over thousands of years, with white quartz sand carried from the Appalachian Mountains and islands still reshaped by wind, waves, and storms. Florida areas include undeveloped beaches, access by automobile, and historic defenses such as Fort Pickens and Fort Barrancas, while Mississippi emphasizes boat-only islands, natural beaches, and Davis Bayou. Hurricanes and the Deepwater Horizon disaster have repeatedly damaged and altered the seashore, making restoration an ongoing part of its history.