Watchung Mountains

The Watchung Mountains are a group of three long low ridges of volcanic origin, between 400 and 500 feet (120 and 150 m) high, lying parallel to each other in northern New Jersey in the United States. The name is derived from the American Native Lenape name for them, Wach Unks (High Hills). In the 18th century, the Euro-American settlers also called them the Blue Mountains or Blue Hills (not to be confused with Blue Mountain in Sussex County). The Watchung Mountains are known for their numerous scenic vistas overlooking the skylines of New York City and Newark, New Jersey, as well as their isolated ecosystems containing rare plants, endangered wildlife, rich minerals, and globally imperiled trap rock glade communities. The ridges traditionally contained the westward spread of urbanization, forming a significant geologic barrier beyond the piedmont west of the Hudson River; the city of Newark, for example, once included lands from the Hudson to the base of the mountains. Later treaties moved the boundary to the top of the mountain, to include the springs.

The Watchungs are basalt uplifts, geologically similar to the Palisades along the Hudson River. In many places, however, the mountains have become sinuous islands of natural landscape within the suburban sprawl covering much of contemporary northeastern New Jersey. Parks, preserves, and numerous historical sites dot the valleys and slopes of the mountains, providing recreational and cultural activities to one of the most densely populated regions of the nation.

The two most prominent ridges, known as First Watchung Mountain (the southeastern ridge) and Second Watchung Mountain (the northwestern ridge), stretch for more than forty miles (64 km) from Somerville (in Somerset County) in the southwest through Morris County, Union County, Essex County, and Passaic County to Mahwah (in Bergen County) in the northeast. Sometimes the less prominent and discontinuous ridge formed by Long Hill, Riker Hill, Hook Mountain, and Packanack Mountain is referred to as Third Watchung Mountain and lies on the northwestern side of Second Watchung Mountain. A parallel series of gaps through all three mountain ridges extends to the west from near Springfield to the northern boundary of Chatham where the Passic River flows through the Third Watchung Mountain.^{[citation needed]}

Often the entireties of First Watchung Mountain and Second Watchung Mountain are erroneously referred to as Orange Mountain and Preakness Mountain. Historically, the names ‘Orange’ and ‘Preakness’ have only been applied to specific sections of these ridges. The confusion appears to have arisen from the fact that First Watchung Mountain is said to be composed of Orange Mountain basalt, while Second Watchung Mountain is composed of Preakness Mountain basalt. The names applied to the basalts are geologic type localities, that is to say, the type of rock found at Orange Mountain is exclusive to all of First Watchung Mountain, while the type of rock found at Preakness Mountain is exclusive to all of Second Watchung Mountain. Similarly to this misinformation about First Watchung Mountain and Second Watchung Mountain, sometimes the Third Watchung Mountain is confused with its basalt type locality, as on some occasions its entire length is erroneously referred to as Hook Mountain.^{[citation needed]}

In addition to the three main ridges of the Watchungs, a smaller fourth ridge exists south of Morristown and west of Third Watchung Mountain. While attaining elevations more than 400 ft (120 m) above sea level, the ridge lacks topographic prominence, only rising to approximately 100 ft (30 m) above the surrounding terrain. Only one portion of the ridge is named, a southern section underlying Harding Township known as Lees Hill.^{[citation needed]}

All of the ridges lie to the east of the higher Appalachian Mountains, which in northern New Jersey often are referred to as the New York - New Jersey Highlands. Together with the Appalachian Mountains to the west, the Watchungs pen in an area formerly occupied by the prehistoric Glacial Lake Passaic. The Great Swamp, a large portion of which is designated as the Great Swamp National Wildlife Refuge, is a remnant of this glacial lake and presently is retained by Third Watchung Mountain.^{[citation needed]}

Although the Watchungs commonly are described in terms of their east-west ridge arrangement (First Watchung Mountain, Second Watchung Mountain, and Third Watchung Mountain), they also are divided into smaller mountain ranges, as well as various named ridges.^{[citation needed]}

Notable ranges and ridges of the Watchungs from north to south include: