Sourland Mountain is a long

ridge A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...

in central

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 ...

, extending from the

Delaware River The Delaware River is a major river in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. From the meeting of its branches in Hancock (village), New York, Hancock, New York, the river flows for along the borders of N ...

at Lambertville to the western end of Hillsborough Township near the community of Neshanic, through Montgomery Township and into Hopewell Township in Mercer County. It comprises the largest contiguous forest in

Central Jersey Central Jersey is the central region of the U.S. state 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, ...

, nearly in area. The highest point is only above sea level, but the way it rises steeply from the surrounding farmland has earned it the title of 'mountain'. The ridge itself sits within a larger area of rough terrain called

The Sourlands The Sourlands is a region in the US state of New Jersey that includes portions of Hunterdon County, Mercer County and Somerset County. It is centered on Sourland Mountain and comprises parts of Lambertville, East Amwell, West Amwell, Hillsbo ...

Toponymy

The origin of the name Sourland is unclear and a few theories exist. It could be derived from the term “''sorrel-land''” which describes the sorrel (reddish-brown) colored shale-bearing soils encountered by the pioneering German farmers, or German immigrants from the

Sauerland The Sauerland () is a rural, hilly area spreading across most of the south-eastern part of North Rhine-Westphalia, in parts heavily forested and, apart from the major valleys, sparsely inhabited. The Sauerland is the largest tourist region in ...

region simply anglicized the name of their home region. Another possible source for the name is from 17th century Dutch settlers who referred to the region as "''sauer landt''" because the region was clearly not suitable for farming. To this day, the area remains relatively undeveloped - besides being unsuitable for farming, the hard igneous rock, nonporous clay soils, steep slopes and perched wetlands create groundwater conditions which make the area difficult for drilling wells and installing septic systems.

History

Before the arrival of Europeans, Sourland Mountain was inhabited by Unami speaking

Lenape The Lenape (, , or Lenape , del, Lënapeyok) also called the Leni Lenape, Lenni Lenape and Delaware people, are an indigenous peoples of the Northeastern Woodlands, who live in the United States and Canada. Their historical territory includ ...

, in particular the Musconetcongs. However, settlements and farms along the mountain seem to have been restricted to river valleys due to the poor, rocky soils upslope. There is evidence indicating the Delaware River likely supported at least one such Lenape settlement at the southern foot of the mountain around present-day

Lambertville, New Jersey Lambertville is a city in Hunterdon County in the U.S. state of New Jersey. As of the 2020 U.S. census, the city's population was 3,906,The Sourland Conservancy – The Sourland Mountain and its people.
/ref> By the end of the 19th century, Sourland Mountain supported a thriving peach farming industry. But a blight just before the start of the new century, as well as a statewide shift to an industrial economy, eventually crippled agriculture on the mountain. Rural villages soon disappeared, and new forests began to grow over abandoned farmland. The only pre-20th century industry that was able to survive into the modern era was rock quarrying –the mountain's

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 ...

was crushed and used to build railroad beds and roads throughout the region. For the first half of the 20th century, Sourland Mountain remained a remote part of New Jersey, with few connections to nearby metropolitan areas. This changed in the 1940s when new road construction made the mountain more accessible, allowing suburbia to begin invading its valleys and slopes. Today the mountain acts as a watershed for surrounding communities, while at the same time providing recreational opportunities to Central New Jersey.

Geography

As a range, Sourland Mountain includes the main ridge and smaller secondary ridges. Near the northern part of the range, Pheasant Hill forms a parallel rise on the east flank of the main ridge. South of Pheasant Hill, a somewhat detached ridge forms Pennington Mountain. This same ridge, which continues to run parallel to the main ridge, is broken in three more places south of Pennington Mountain, forming (from north to south) Mount Canoe, Baldpate Mountain, and Strawberry Hill. A knob in the shallow valley between Strawberry Hill and the southernmost stretch of the main ridge forms Belle Mountain. Goat Hill comprises the highest point of the main ridge before reaching the southernmost end of Sourland Mountain at the

. Partly adjacent to Sourland Mountain is a sizeable traprock ridge which extends eastward from Pennington Mountain for approximately nine miles, forming (from west to east) Mount Rose, Rocky Hill, and Ten Mile Run Mountain. West of the main ridge, near Flemington, is Prospect Hill, a volcanic remnant lying along the western edge of the

Amwell Valley The Amwell Valley is a small valley in Hunterdon County, New Jersey, between the Hunterdon Plateau and the Sourlands. It comprises Stockton, parts of Delaware Township, West Amwell, East Amwell, Flemington and Raritan Township. The region ...

. The hill appears to be geologically linked to Sourland Mountain by a volcanic dike running mostly beneath the surface.

Geology

Sourland Mountain was formed 200 million years ago by a plutonic

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

of a hard

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock ...

diabase Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-graine ...

, into the Brunswick Shale. The intrusion occurred as tectonic forces created 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 ...

, a prehistoric rift valley active near the rift which ultimately spread North America and Africa apart. The parallel ridges of the mountain were probably formed by magma seeping up through linear faults created during the rifting process During the early

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), 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 J ...

the rift which formed the Newark Basin failed, and the intrusion which would eventually become Sourland Mountain ceased growing. Initially, the vast majority of volcanic material remained within the crust. However, the diabase and related

hornfels Hornfels is the group name for a set of contact metamorphic rocks that have been baked and hardened by the heat of intrusive igneous masses and have been rendered massive, hard, splintery, and in some cases exceedingly tough and durable. These pro ...

which form the backbone of the mountain are a type of highly erosion resistant stone known as

. Consequently, millions of years of erosion lowered the more easily worked shale surrounding the intrusion, turning it into the elevated ridges which currently comprise Sourland Mountain. The

Palisades Sill The Palisades Sill is a Triassic, 200 Ma diabase intrusion. It extends through portions of New York and New Jersey. It is most noteworthy for The Palisades, the cliffs that rise steeply above the western bank of the Hudson River. The ideal loc ...

, in northeastern New Jersey and southeastern New York, was not only formed under similar circumstances to Sourland Mountain, it is at least partly contiguous with it. The ridge forming Mount Rose, Rocky Hill, and Ten Mile Run Mountain, is a continuation of the Palisades which connects to Pennington Mountain. South of Pennington Mountain the Palisades sill and Sourland Mountain's eastern ridge are essentially the same feature. Like the Palisades, Sourland Mountain exhibits volcanic dikes which extend away from the main ridge. One such dike extending northwest from Sourland Mountain has been determined to be responsible for the creation of Prospect Hill, an extrusive basalt peak near Flemington, New Jersey. Prospect Hill marks the only known location where Sourland Mountain's magma actually erupted to the surface. In this respect, it is similar to

Snake Hill Snake Hill (known officially as Laurel Hill) is an igneous rock intrusion jutting up from the floor of the Meadowlands in southern Secaucus, New Jersey, at a bend in the Hackensack River., Variant name: Snake Hill It was largely obliterated in t ...

, which it most likely a volcanic plug linked to the Palisades. One of the key differences between Sourland Mountain and the other volcanic mountains of the Newark Basin, including the Watchungs and the Palisades, is that it has not been touched by glaciers. This has left the mountain with a mantle of Triassic

argillite :''"Argillite" may also refer to Argillite, Kentucky.'' Argillite () is a fine-grained sedimentary rock composed predominantly of indurated clay particles. Argillaceous rocks are basically lithified muds and oozes. They contain variable amounts ...

, which covers much of the underlying trap rock and comprises the bulk of Pheasant Hill.Stanford, Scott D. et al. ''Earthquake Loss Estimation Study for Somerset County, NJ: Geologic Component.'' New Jersey Geological Survey, March 2008.

/ref> The impermeability of argillite is primarily to blame for Sourland Mountain's extremely poor aquifer.

Wildlife

Sourland Mountain is in the

Northeastern coastal forests The Northeastern coastal forests are a temperate broadleaf and mixed forests ecoregion of the northeast and middle Atlantic region of the United States. The ecoregion covers an area of 34,630 sq miles (89,691 km2) encompassing the Piedmont a ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

It is an environmentally sensitive area and is home to several rare and threatened plants and animals, including:

trout lilies ''Erythronium'', the fawn lily, trout lily, dog's-tooth violet or adder's tongue, is a genus of Eurasian and North American plants in the lily family, most closely related to tulips. The name Erythronium derives from Ancient Greek () "red" in ...

, wood anemones,

ginseng Ginseng () is the root of plants in the genus ''Panax'', such as Korean ginseng ('' P. ginseng''), South China ginseng ('' P. notoginseng''), and American ginseng ('' P. quinquefolius''), typically characterized by the presence of ginsenosides an ...

spotted salamander The spotted salamander or yellow-spotted salamander (''Ambystoma maculatum'') is a mole salamander common in eastern United States and Canada. The spotted salamander is the state amphibian of Ohio and South Carolina. This salamander ranges from N ...

pileated woodpecker The pileated woodpecker (''Dryocopus pileatus'') is a large, mostly black woodpecker native to North America. An insectivore, it inhabits deciduous forests in eastern North America, the Great Lakes, the boreal forests of Canada, and parts of the ...

bobcat The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the IUC ...

wood turtle The wood turtle (''Glyptemys insculpta'') is a species of turtle endemic to North America. It is in the genus ''Glyptemys'', a genus which contains only one other species of turtle: the bog turtle (''Glyptemys muhlenbergii'' ). The wood turtle ...

barred owl The barred owl (''Strix varia''), also known as the northern barred owl, striped owl or, more informally, hoot owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus '' Strix'', whic ...

bobolink The bobolink (''Dolichonyx oryzivorus'') is a small New World blackbird and the only member of the genus ''Dolichonyx''. An old name for this species is the "rice bird", from its tendency to feed on cultivated grains during winter and migration. ...

Cooper's hawk Cooper's hawk (''Accipiter cooperii'') is a medium-sized hawk native to the North American continent and found from southern Canada to Mexico. This species is a member of the genus ''Accipiter'', sometimes referred to as true hawks, which are f ...

grasshopper sparrow The grasshopper sparrow (''Ammodramus savannarum'') is a small New World sparrow. It belongs to the genus '' Ammodramus,'' which contains three species that inhabit grasslands and prairies. Although sometimes found in crop fields and they will re ...

Savannah sparrow The Savannah sparrow (''Passerculus sandwichensis'') is a small New World sparrow. It was the only member of the genus '' Passerculus'' and is typically the only widely accepted member. Comparison of mtDNA NADH dehydrogenase subunit 2 and 3 sequ ...

upland sandpiper The upland sandpiper (''Bartramia longicauda'') is a large sandpiper, closely related to the curlews. Older names are the upland plover and Bartram's sandpiper. In Louisiana, it is also colloquially known as the papabotte. It is the only member ...

, and the

scarlet tanager The scarlet tanager (''Piranga olivacea'') is a medium-sized American songbird. Until recently, it was placed in the tanager family (Thraupidae), but it and other members of its genus are now classified as belonging to the cardinal family (Cardin ...

. The Sourlands serve as a stopover area for migratory birds that travel between South and Central America and the Arctic as well as forest birds migrating between

Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...

, and

Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- mo ...

. The area also supports a large population of deep-woods birds such as scarlet tanagers and barred owls. Being the largest contiguous forest between the

Pine Barrens Pine barrens, pine plains, sand plains, or pineland areas occur throughout the U.S. from Florida to Maine (see Atlantic coastal pine barrens) as well as the Midwest, West, and Canada and parts of Eurasia. Perhaps the most well known pine-barre ...

and the New Jersey Highlands, it is critical to the survival of neotropical migrant birds and other rare species of plants and animals. D&R Greenway Land Trust's partner in Mexico, Amigos de Calakmul, protects bird habitat at the southern end of the migratory flyway.

Recreation

Small parks and access points make the mountain popular for hiking, mountain biking, hunting, and bird watching. Rock climbing is permitted in certain parks such as Sourland Mountain Preserve in Somerset County, but not in others such as Sourland Mountain Nature Preserve in Hunterdon County. The largest park is the Sourland Mountain Preserve in Somerset County. Nearby is the Sourland Mountain Nature Preserve,Hunterdon County: Sourland Mountain Nature Preserve
, accessed November 9, 2006 located in Hunterdon County.

Notable inhabitants

Notable residents of the Mountain include: playwrights

Eugene O'Neill Eugene Gladstone O'Neill (October 16, 1888 – November 27, 1953) was an American playwright and Nobel laureate in literature. His poetically titled plays were among the first to introduce into the U.S. the drama techniques of realism, earlier ...

, aviator

Charles Lindbergh Charles Augustus Lindbergh (February 4, 1902 – August 26, 1974) was an American aviator, military officer, author, inventor, and activist. On May 20–21, 1927, Lindbergh made the first nonstop flight from New York City to Paris, a distance o ...

, patriot John Hart (signer of the Declaration of Independence), the painter

George Bellows George Wesley Bellows (August 12 or August 19, 1882 – January 8, 1925) was an American realism, American realist painting, painter, known for his bold depictions of urban life in New York City. He became, according to the Columbus Museum of Art ...

, and freed slave and tavern owner

Sylvia Dubois Sylvia Dubois (c. 1788/89 – May 27, 1888), also spelled as Silvia Dubois or Sylvie Dubois, was an African-American woman born into slavery who became free after striking her slave mistress. After gaining her freedom, Dubois moved to New Jersey, ...

. In March 1932, the mountain was the scene of the notorious kidnapping and murder of the Lindbergh baby. The Lindberghs had chosen the mountain for their new home precisely because of its isolation and inaccessibility.

References

External links

The Sourland Conservancy

Sourland Mountain Special Resource Area Designation

NY-NJTC: Sourland Mountain Preserve Trail Details and Info

Sourlands
A documentary film released June 2012. {{Authority control Ridges of New Jersey Landforms of Hunterdon County, New Jersey Landforms of Mercer County, New Jersey Landforms of Somerset County, New Jersey Igneous petrology of New Jersey Triassic magmatism Jurassic magmatism Igneous intrusions Mafic intrusions