Geography of New Jersey: Pine Barrens, Palisades & the Jersey Shore

New Jersey is the fifth-smallest state at 22,591 square km but spans four physiographic provinces, from the Appalachian ridges in the northwest to the Atlantic barrier beaches in the southeast. Its compact size belies extraordinary geographic diversity.

Introduction

The state's most distinctive landscape is the Pine Barrens, a 4,500 square km wilderness of pine and oak forest, cedar swamps, and tea-colored streams overlying a vast aquifer. This is the largest tract of open space on the Mid-Atlantic coast between Boston and Richmond.

New Jersey sits at the boundary between the glaciated and unglaciated portions of the eastern United States — the terminal moraine of the last ice age runs through the middle of the state, creating a visible line between the rocky, hilly north and the sandy, flat south.

Major Geographic Features

Palisades

The Palisades are a dramatic cliff of 200-million-year-old diabase (a volcanic intrusion related to basalt) rising 90 meters above the Hudson River along New Jersey's northeastern border. The columns formed when magma intruded between layers of sandstone and cooled slowly, creating the distinctive columnar jointing. The Palisades extend 32 km from Bayonne to the New York border and are protected as Palisades Interstate Park.

Delaware Water Gap

The Delaware Water Gap is a dramatic water gap where the Delaware River cuts through Kittatinny Mountain in a notch 300 meters deep and less than 300 meters wide at river level. Mount Tammany on the New Jersey side rises to 430 meters directly above the river. The gap was carved over millions of years as the river maintained its course while the mountain was uplifted around it — a classic example of an antecedent stream.

Pine Barrens

The New Jersey Pine Barrens (Pinelands) cover 4,500 square km of sandy, acidic terrain in southern New Jersey, protected as a UNESCO Biosphere Reserve and National Reserve. The Pinelands sit atop the Kirkwood-Cohansey Aquifer, which holds an estimated 64 trillion liters of water. The ecosystem supports unique species including the Pine Barrens treefrog and curly grass fern. The streams are stained brown by natural tannins and iron, creating a distinctive "tea water" appearance.

Jersey Shore & Barrier Islands

New Jersey has 210 km of Atlantic coastline, much of it consisting of barrier islands and barrier spits. Sandy Hook, a recurved spit at the northern end, extends 10 km into the entrance of New York Harbor. Long Beach Island, a 30-km barrier island, is one of the most developed. The shore is subject to frequent nor'easters and hurricanes — Hurricane Sandy in 2012 caused catastrophic damage, reshaping portions of the coastline permanently.

Kittatinny Ridge & High Point

Kittatinny Ridge runs 65 km across northwestern New Jersey as part of the Appalachian Ridge and Valley province. High Point at 550 meters (1,803 feet) is the state's highest point, located at the ridge's northern end. The Appalachian Trail follows the ridgeline for its 116-km traverse of New Jersey. The ridge is composed of resistant Silurian conglomerate and sandstone that has withstood erosion better than the softer rocks in the valleys on either side.

Highlands & Glacial Lakes

The New Jersey Highlands are a belt of Precambrian gneiss and granite hills between the Kittatinny Ridge and the Piedmont, reaching 400 meters elevation. The region was glaciated and features numerous lakes including Lake Hopatcong (10.5 sq km, New Jersey's largest lake), Greenwood Lake, and dozens of smaller glacial lakes and ponds. The terminal moraine of the Wisconsinan glaciation runs through the Highlands, creating a visible boundary between the hilly north and the flatter south.

Key Geographic Facts

• High Point at 550 m (1,803 ft) is New Jersey's highest point
• The Pine Barrens cover 4,500 sq km and overlie an aquifer holding 64 trillion liters of water
• New Jersey has 210 km of Atlantic coastline
• The Palisades cliffs rise 90 m above the Hudson River
• New Jersey spans four physiographic provinces

Fun Facts

• The Pine Barrens aquifer holds enough water to cover the entire state to a depth of 3 meters
• The Palisades columns are 200-million-year-old volcanic rock formed when the Atlantic was first opening
• The glacial terminal moraine runs through the middle of New Jersey, dividing the rocky north from the sandy south
• The Delaware Water Gap is a textbook example of an antecedent stream, where the river is older than the mountain

Final Thoughts

New Jersey packs glaciated mountains, a volcanic cliff along the Hudson, one of the East Coast's great wilderness areas in the Pine Barrens, and 210 km of dynamic barrier coast into the nation's fifth-smallest state. The glacial terminal moraine running through the middle of the state creates a visible divide between two very different New Jerseys — rocky and hilly in the north, sandy and flat in the south.