From the Maryland Department of Natural Resource's website:

Calvert Cliffs State Park is a day-use park featuring a sandy beach, unique fossils, recycled tire playground, a freshwater and tidal marshland and 13 miles of hiking trails located in Calvert County. The massive cliffs from which Calvert Cliffs State Park was named dominates the shoreline of the Chesapeake Bay for thirty miles in Calvert County and were formed over 15 million years ago when all of Southern Maryland was covered by a warm, shallow sea. When the sea receded 20-25 million years ago, marking the end of the Miocene period, cliffs were exposed and began eroding. Today these cliffs reveal the remains of prehistoric species ncluding sharks, whales, rays, and seabirds that were the size of small airplanes.

A hike of 2 miles is taken from the parking lot, along an unimproved trail to the cliffs/beach area. Over 600 species of fossils have been identified from these cliffs, with the teeth of various species of shark as the most abundant fossils. Visitors may hunt for fossils on the open beach area and keep what they find, but always be mindful that fossils help tell the story of the past. So be sure to leave a piece of the story for other visitors.

Fossil hunting around Calvert Cliffs can also be done at Flag Pond; Chesapeake Beach: Bayfront Park, also known as Brownies Beach. This site is accessible by foot only during low tide; at high tide, the water extends to the base of the cliffs. The exposure here is in the Calvert Formation. Matoaka Cottages, south of Prince Frederick, is privately owned property. For the cost of parking, the owners will allow families access to the beach and cliff area.