Cushetunk Mountain (formerly Mount Ployden and Pickel's Mountain occasionally Mount Cushetunk or Coshanton) is a ring shaped
mountain
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually highe ...
in the
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...
of
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
Hunterdon County
Hunterdon County is a county located in the western section of the U.S. state of New Jersey. As of the 2020 U.S. census, the county's population was 128,947, making it the state's 18th-most populous county,LenapeNative Americans called the mountain "Cushetunk" meaning "place of hogs" after the wild hogs found there.Cushetunk Mountain , County of Hunterdon Dept of Parks and Recreation – Cushetunk Mountain Preserve In the 1960s, the valley at the heart of the mountain was dammed and filled with water to create Round Valley Reservoir. Today, the mountain and its accompanying lake act as a vital water supply to Central New Jersey, while at the same time providing numerous recreational opportunities to the region.
Raritan Township, New Jersey
Raritan Township is a township in Hunterdon County, New Jersey, United States. As of the 2010 United States Census, the township's population was 22,185, reflecting an increase of 2,376 (+12.0%) from the 19,809 counted in the 2000 Census, whi ...
is a horseshoe shaped mountain with the tips of its two prongs ending in the west at the edge of the New Jersey Highlands. The mountain's U-shaped arc is approximately in diameter, with the more massive portion of the mountain occupying the southwest corner of the ridgeline. A deep man-made lake, Round Valley Reservoir, occupies the valley at the center of the horseshoe.
Cushetunk Mountain is occasionally referred to as a mountain range and includes Round Mountain, a peakMountain Zone – Round Mountain Summit, New Jersey /ref> located about south of Cushetunk Mountain in Readington. Round Mountain is linked to Cushetunk Mountain by a sheet of
intruded
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form '' intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March 2 ...
diabase rock running beneath the surface.
Located on the mountains are the communities of Cushetunk, Lebanon and Lebanon Borough. In Clinton township the mountains Stretch from the south west part of the township to north central part. Lebanon covers the whole mountain (with the exception of Lebanon Borough an Cushetunk).
History
Before the arrival of Europeans, Cushetunk Mountain was inhabited by Unami speaking Lenape, particularly the Musconetcongs who ranged between Cushetunk Mountain and
Sourland Mountain
Sourland Mountain is a long ridge in central New Jersey, extending from the Delaware River at Lambertville to the western end of Hillsborough Township near the community of Neshanic, through Montgomery Township and into Hopewell Township ...
to the south.Wittwer, Norman C ''The Dawn of Hunterdon'' County of Hunterdon: History. Accessed May 16, 2009 An interesting claim put forward by Beauchamp Plantagenet, one of the first Europeans to explore the area around the mountain, states that a Native American king held his seat in a place resembling the valley formed by Cushetunk Mountain. The claim exists today as a legend, and no evidence has ever been found confirming Plantagenet's story of a ‘Raritan king’.
Two famous names from New Jersey's colonial history owned land on the north slope of Cushetunk Mountain in Potterstown (part of Readington and Clinton Township). One was John Stevens, a delegate to the Continental Congress, whose grandson founded
Stevens Institute of Technology
Stevens Institute of Technology is a private research university in Hoboken, New Jersey. Founded in 1870, it is one of the oldest technological universities in the United States and was the first college in America solely dedicated to mechanical ...
. The other was
Lord Stirling
William Alexander, also known as Lord Stirling (1726 – 15 January 1783), was a Scottish-American major general during the American Revolutionary War. He was considered male heir to the Scottish title of Earl of Stirling through Scottish line ...
, an
American Revolutionary War
The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, was a major war of the American Revolution. Widely considered as the war that secured the independence of t ...
General who was ranked 3rd or 4th behind
George Washington
George Washington (February 22, 1732, 1799) was an American military officer, statesman, and Founding Father who served as the first president of the United States from 1789 to 1797. Appointed by the Continental Congress as commander of ...
.Readingtown Township History County of Hunterdon
Historically, wildlife at the mountain included apex predators that are no longer found in the region. A story from the colonial era involving Dr. John Rockhill, a member of the Society of Friends and supposedly Hunterdon's County's first physician, indicates that Cushetunk Mountain and neighboring Round Mountain were known to harbor wolves. It is also noted that settlers in nearby Flemington had to defend against these wolves during the winter.Quarrie, George ''Within a Jersey circle; tales of the past, grave and gay, as picked up from old Jerseyites'' Unionist-Gazette Association, Somerville, NJ, 1910.
Prior to the 1960s, when the valley surrounded by Cushetunk Mountain was dammed to form Round Valley Reservoir, the mountain was useful as a timber source. Farming use was limited due to the hard diabase rock in the mountain's soil.
Sourland Mountain
Sourland Mountain is a long ridge in central New Jersey, extending from the Delaware River at Lambertville to the western end of Hillsborough Township near the community of Neshanic, through Montgomery Township and into Hopewell Township ...
, Cushetunk Mountain formed approximately 200 million years ago around the
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...
/
Jurassic
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...
boundary as an intrusion of igneous rock, diabase, into local shale and sandstone. The intrusion occurred when the
Newark Basin
The Newark Basin is a sediment-filled rift basin located mainly in northern New Jersey but also stretching into south-eastern Pennsylvania and southern New York. It is part of the system of Eastern North America Rift Basins.
Geology
Approximat ...
, an aborted
rift zone
A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent. Believed t ...
that formed as
Pangaea
Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...
began to break up, was still volcanically active. Originally, it was thought that Cushetunk Mountain was formed well after the nearby
Watchung Mountains
The Watchung Mountains (once called the Blue Hills) are a group of three long low ridges of volcanic origin, between high, lying parallel to each other in northern New Jersey in the United States. The name is derived from the American Native Lena ...
, also of volcanic origin. The theory was that the deposition of sediment into the Newark Basin was still occurring after the Watchungs were extruded, which explained how Cushetunk Mountain was able to intrude into strata above the height of the Watchungs. However, it is now known that Cushetunk Mountain, as well as other intrusive bodies in the Newark Basin, are at least 10 million years older than the Watchungs, which implies that erosion and/or uplift must have occurred after Cushetunk Mountain was intruded in order to allow the Watchungs to form at the surface.Armstrong, R. L., Besancon, J. A Triassic time scale di-lemma: K-Ar Dating of Upper Triassic Mafic Igneous Rocks, Eastern U.S.A. and Canada, and Post-Upper Triassic Plutons, Western Idaho, U.S.A. ''Eclogae Geol. Helv.'', Vol. 63, p. 15-28, 1970. Both Cushetunk Mountain and the Watchungs were elevated after millions of years of erosion stripped away the overlying sandstone and shale strata and exposed their durable
trap rock
Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. ...
masses to the surface.U.S. Geological Survey - NYC Regional Geology, Mesozoic Basins /ref>
Contrary to popular belief, the ring-like shape of the mountain does not represent a crater, particularly since the mountain was formed primarily within the Earth. Instead, the mountain's shape seems to be the result of an intruding sheet of magma becoming dramatically flexed as it penetrated local strata. Round Mountain, just to the south of Cushetunk Mountain, formed as the intruding sheet that created Cushetunk Mountain reached a syncline.
A unique feature of Cushetunk Mountain's geology is that the igneous intrusion forming the mountain partly overlaps Paleozoic limestone west of the
Ramapo Fault
The Ramapo Fault zone is a system of faults between the northern Appalachian Mountains and Piedmont areas to the east. Occurring just south of Molasses Hill Rd in Clinton Township, the overlap is significant for two reasons. First, the overlap marks one of the only locations in the
Newark Basin
The Newark Basin is a sediment-filled rift basin located mainly in northern New Jersey but also stretching into south-eastern Pennsylvania and southern New York. It is part of the system of Eastern North America Rift Basins.
Geology
Approximat ...
where an intrusion successfully crossed the Ramapo fault and effectively spilled over the western edge of the basin. Second, the trap rock comprising the intrusion at this location is fine grained and unlike the dense, coarse diabase common to Cushetunk Mountain. It is thought that this is because the intrusion erupted to the surface as it overran the Paleozoic limestone.
Ecology
While most of the mountain ridges in New Jersey run generally north to south, Cushetunk Mountain primarily has an east-west ridge orientation because of the elongated north and south prongs of its horseshoe-like ridge. This produces significantly different microclimates between the north facing and south facing slopes of the mountain.Cantlon, J. E. 1953. Vegetation and microclimates on north and south slopes of Cushetunk Mountain, New Jersey. ''Ecological Monographs'' 23: 241-270. On south facing slopes, the air temperature near the ground is consistently higher than on the north facing slopes, which do not receive as much sunlight. In terms of ecology this creates a noticeable impact on Cushetunk Mountain's vegetation.
Because the north slope of the mountain is cooler and shaded, moisture is more easily retained. This results in larger trees, as well as the growth of trees not seen on southern facing slopes. These trees include
black birch Black birch is a common name for several trees, and may refer to:
* Asian black birch, the English name for '' Betula dahurica'', tree species native to eastern Asia
* Black birch, a common name for ''Betula lenta'', tree species native to eastern ...
,
tulip tree
''Liriodendron'' () is a genus of two species of characteristically large trees, deciduous over most of their populations, in the magnolia family (Magnoliaceae).
These trees are widely known by the common name tulip tree or tuliptree for their ...
sugar maple
''Acer saccharum'', the sugar maple, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is native to the hardwood forests of eastern Canada and eastern United States. Sugar maple is best known for being the prim ...
. Shrubs are abundant in the understory of the northern slopes, as well as herbs typical of more northern forests, including wild ginger, wild sarsaparilla, black snakeroot, and columbine.
On the warmer, dryer southern slopes
chestnut oak
''Quercus montana'', the chestnut oak, is a species of oak in the white oak group, ''Quercus'' sect. ''Quercus''. It is native to the eastern United States, where it is one of the most important ridgetop trees from southern Maine southwest ...
and
red oak
The genus ''Quercus'' contains about 500 species, some of which are listed here. The genus, as is the case with many large genera, is divided into subgenera and sections. Traditionally, the genus ''Quercus'' was divided into the two subgenera ''C ...
prevail, although the trees are also common to the northern slopes. In the understory,
dogwood
''Cornus'' is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shru ...
is dominant, and the diversity and number of shrubs is reduced. Grasses and sedges are the most prevalent ground cover.
Wildlife supported by Cushetunk Mountain includes a variety of woodland birds, including a nesting pair of bald eagles. Groundwater seeps, particularly on the northern slopes, provide habitat to amphibians, while outcrops of trap rock offer ideal environments for small reptiles.