The second zone, The Highlands, immediately southeast of the Appalachian zone, extends from the Delaware River into New York. Its southeastern boundary passes near Morristown and Boonton. This zone is from ten to twenty miles wide. Its height generally varies from 900 feet to 1400 feet. Hamburg Mountain and Wawayanda Mountain reach an altitude of 1469 feet. The Highlands, as well as the Appalachian zone, belong to the Appalachian region, but in New Jersey the term "Appalachian" is applied only to the region consisting of Kittatinny Mountain and Valley.
Relief map of New Jersey
The Highlands contain many irregular mountain masses, interspersed with fertile valleys, and much forest land. The zone contains, besides, many lakes, most of which are of glacial origin. The section is consequently one of great natural beauty, and is a popular resort for many who desire out-door recreation. There is much fertile farm land and land suitable for grazing. Parts of it are specially suitable for the raising of peaches and other fruits. It contains many valuable mineral deposits, including gravel, cement rock, zinc, and iron.
Next to the Highlands and parallel with it is the Piedmont Plateau. This extends from the Delaware River to the northeast corner of the state and is about thirty miles wide. Its southeastern boundary is a line running from Trenton to Woodbridge in Middlesex County, which represents in this state the Fall Line (Sec. 47). It comprises about one fifth of the area of the state. Its elevation varies from sea level to about 900 feet.
The Piedmont Plateau is characterized by the presence of red sandstone and shale. Its surface is very irregular. In its eastern part it is undulating or rolling. In the western, it contains higher lands which may be called plateaus. It contains also irregular ridges such as the Watchung Mountains, the Palisades, and the mountains in Hunterdon County. The Watchung Mountains and the Palisades are composed of trap rock, which in a molten condition was forced up through overlying rock strata. The eastern sides of these trap ridges are steep slopes. The underlying sandstone has been worn away while the harder trap rock has resisted erosion.
The Palisades of the Hudson
The Falls of the Passaic River at Paterson are located in this section. These falls, which are seventy feet high, were formed by the water passing over the hard trap rock and wearing away the softer rock below.
Because of the nearness of the Piedmont Plateau to the great commercial centers of the country and the excellent facilities for transportation, most of the larger cities of the state are located in this zone.