Close to downtown Eastport, the easternmost city in the United States, Shackford Head State Park encompasses 90 acres on Moose Island overlooking Cobscook Bay. This promontory at the entrance to Cobscook Bay encircles the west side of Broad Cove.

Several miles of trails cross the headland. A hiking trail from the parking area leads through woods to a rocky headland 173 feet above sea level, passing several pocket beaches and protected coves. From this outlook, visitors can see Campobello Island in New Brunswick, Canada, the town of Lubec, and the Eastport cargo pier on Estes Head, as well as aquaculture pens where Atlantic salmon are raised. Park trails afford great opportunities for wildlife watching as well - with warblers and hermit thrushes in the woodland areas, and bald eagles, common terns and spotted sandpipers along the shore. Ornithologists have documented 28 different bird species nesting on the headland.

Shackford Head is named for one of the town's earliest settlers, Capt. John Shackford - a Revolutionary War soldier who arrived with his family about 1783. Born and raised in Massachusetts, he spent most of his 87 years based in Eastport. Capt. Shackford owned the headland and used Broad Cove as his ship's anchorage. He died December 25, 1840 and is buried beside his wife in the nearby Hillside East Cemetery.

During the early 1900s, five ships that had served in the Civil War (the U.S.S. Franklin; U.S.S. Minnesota; U.S.S. Richmond, U.S.S. Voymon and U.S.S. Wabash) were burned for salvage (recovery of brass and iron) at Cony Beach on Shackford Head. A memorial plaque on site provides more details about this chapter in the headland's history.

In the 1970s, Shackford Head was the site of a proposed oil refinery that the Pittston Company sought to construct - a plan that met with strong opposition due to Cobscook Bay's navigational hazards and exceptional wildlife values. When the property came up for sale in 1988, the Eastport Land Trust sought assistance from the State's Land for Maine's Future (LMF) Program to keep the land wild for the public to enjoy. The LMF Program helped fund its acquisition in 1989 and the Maine Department of Conservation now owns and manages the land.