Hatches Harbor was originally the mouth of a large water body known as Race Run. Hatches Harbor Dike was constructed in 1930 to lower the water level and reduce the mosquito breeding grounds in the 400-acre salt marsh of Race Run plain. But six decades later, recognizing the upset caused to the marshland ecosystem, the Park Service began installing culverts through which salt water could once again flow.
Hatches Harbor was the scene of a spectacular grounding in 1960. The 258-foot freighter Monica Smith, on its way to Nova Scotia, was beached so high and dry that it looked as if it had been constructed on land, or set down there overnight by the hand of a God with a sense of humor.
On the bay side of the marsh are the ruins of what may have been a coal barge.