Penobscot Bay

The chief tributary of Penobscot Bay, the Penobscot River, winds through a total of 264 miles with a drainage basin of 8,610 square miles. The river includes four branches each originating in mountain lakes. The Penobscot River is the longest river system contained entirely within the state of Maine. The islands of the Penobscot Bay archipelago are innumerable but some of the larger include Deer Isle, Isle au Haut, Matinicus Isle, Nautilus Island, North Haven and Vinalhaven.