The upper Damariscotta River is famous for its enormous oyster shell heaps, also called middens. Native Americans created the middens over a period of about a thousand years, between 2,200 and 1,000 years ago.

The eastern bank of the Damariscotta River once contained an even larger shell heap named Whaleback because of its shape. Much of this midden was removed in the late 1880s to supply a factory built here to process the oyster shells into chicken feed. As a result, only a small portion of Whaleback remains.

The site includes a scenic walking trail maintained by the Damariscotta River Association. It includes an old orchard, bird watching, and the remains of the shell middens. The view from across the river includes the Glidden Midden, another large shell heap created in prehistoric times.