Calvert Cliffs State Park Professional Review and Guide

"A shallow sea once covered all of southern Maryland. When it receded twenty to twenty-five million years ago, the steep shoreline now known as Calvert Cliffs were exposed and began to erode. They're still eroding today (making them dangerous to walk on), continually revealing the East Coast's largest assemblage of fossils."

--Bill and Mary Burnham, Best Hikes Near Washington D.C. (Falcon Guides).