Great Bay is located in southern New Jersey's Atlantic Coastal Plain in Ocean and Atlantic Counties, about ten miles (13 km) north of Atlantic City and 87 mi (140 km) south of New York City. The Mullica River flows into the bay, and together they form the Mullica River - Great Bay estuary habitat. The bay is connected to the Atlantic Ocean via the Little Egg Inlet. Great Bay is considered one of the least-disturbed marine wetlands habitats in the northeastern United States.