Tucked into a corner of Little Deer Isle, less than a mile from the causeway connecting Deer Isle-Stonington to the mainland, is one of the most unique spots in New England.
Pine Hill Preserve, located on Blastow Cove Road, is a great detour for a day spent visiting the area. Typically, you visit for a quick hike up a steep trail on the rocky outcrop, resulting in a fantastic view of Deer Isle, Eggemoggin Reach and far-off mountains.
But what’s different about Pine Hill is that those rocks that make up the outcrop are some of the oldest in North America. They’re made of an extremely uncommon rock type called serpentinized peridotite, a coarse-grained igneous rock. Geologists think Pine Hill is the throat of an ancient volcano, but more recently, it has been theorized that it’s simply a crack in the Earth’s crust through which magma was forced more than 200 million years ago.
Other theories claim it is a chunk of oceanic crust that was caught up when North America crashed into other tectonic plates more than 400 million years ago — the event that created the coastal mountains in Maine.
Regardless of its origin, the unique chemistry of the rocks means the soil is high in minerals such as chromium and nickel, usually toxic to plants. But nature finds a way, and Pine Hill is rich with more than 70 species of lichens, mosses, ferns and other plants, 16 of which are found nowhere else in Maine. This makes it important to be careful not to disturb anything at the site. One species of Woodsia fern found at Pine Hill is found in only one other place on Earth — the Arctic. Island Heritage Trust of Deer Isle-Stonington has information online at islandheritagetrust.org.