Sussex County

County in northern New Jersey, bounded to the west by the Delaware River and to the north by New York; area 1,362 sq km/526 sq mi; population (1990) 131,000. Its seat is Newton; other municipalities include Franklin, Hamburg, Ogdensburg, and Sparta.

The county is mountainous and lake-filled, with Stokes State Forest and High Point State Park in its northwest. It is largely agricultural, with farms that produce fruit, vegetables, and livestock, some light manufacturing, resorts, and an increasing suburban component.