(MD) (Smithsonian Associates) The geography and environment of the Mid-Atlantic were shaped over hundreds of millions of years, reflecting influences that include the impact of a massive meteor; four tectonic mountain-building events; ice sheets and tropical oceans; plants and animals; and at least 15,000 years of human habitation.

Environmental historian and storyteller Hayden Mathews interprets the many layers of the region’s natural history as he leads a tour to three sites in Calvert County, Maryland: Battle Creek Cypress Swamp, Calvert Marine Museum, and Flag Ponds Nature Park.