Mainland beaches stretch unbroken for many miles along the edges of major land masses. They receive sediment from nearby rivers and eroding bluffs. Examples of mainland beaches include coasts of the Great Lakes, northern New Jersey, and southern California. Pocket beaches form in small bays surrounded by rocky cliffs or headlands. The headlands protect the sandy alcoves from erosion by winter storms and strong currents.
Pocket beaches are common in New England and the Pacific Northwest.
Barrier beaches are found along the Gulf of Mexico, the east coast, and much of Alaska. They are part of complex integrated systems of beaches, dunes, marshes, bays, tidal flats, and inlets. The barrier islands and beaches are constantly migrating, eroding, and building in response to natural processes and human activities. They form in sheltered coastal environments often in conjunction with river deltas, barrier islands, and estuaries. They are rich in wildlife resources and provide nesting grounds and important stopovers for waterfowl and migratory birds as well as spawning areas and valuable habitats for commercial and recreational fish.