South Mountain is a colloquial name applied to an

Appalachian Mountain The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...

range extending north and northeast along the south side of

Lebanon Valley The Lebanon Valley is a geographic region that lies between South Mountain and the Ridge and Valley Province of eastern Pennsylvania. The valley lies almost entirely within Lebanon and Berks counties in Pennsylvania. Portions of the valley lie ...

to the

Lehigh Valley The Lehigh Valley (), known colloquially as The Valley, is a geographic region formed by the Lehigh River in Lehigh County and Northampton County in eastern Pennsylvania. It is a component valley of the Great Appalachian Valley bound to the no ...

region of eastern

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. South Mountain includes the southernmost cluster of peaks that straddle Berks, Lancaster, and

Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus lie ...

counties and the northernmost end of the ridge in the on which

Lehigh University Lehigh University (LU) is a private research university in Bethlehem, Pennsylvania in the Lehigh Valley region of eastern Pennsylvania. The university was established in 1865 by businessman Asa Packer and was originally affiliated with the Epi ...

Bethlehem Bethlehem (; ar, بيت لحم ; he, בֵּית לֶחֶם '' '') is a city in the central West Bank, Palestine, about south of Jerusalem. Its population is approximately 25,000,Amara, 1999p. 18.Brynen, 2000p. 202. and it is the capital ...

is built in the Lehigh Valley. The mountain borders Emmaus just south of

Allentown Allentown may refer to several places in the United States and topics related to them: *Allentown, California, now called Toadtown, California *Allentown, Georgia, a town in Wilkinson County *Allentown, Illinois, an unincorporated community in Taze ...

and comprises a ridge of low mountains passing east of

Reading Reading is the process of taking in the sense or meaning of letters, symbols, etc., especially by sight or touch. For educators and researchers, reading is a multifaceted process involving such areas as word recognition, orthography (spell ...

, and then extends due west. South Mountain is a continuation of the

New England Province The New England province is a physiographic province of the larger Appalachian division of eastern North America. The province consists of the Seaboard Lowland, New England Upland, White Mountain, Green Mountain, and Taconic sections. Geology ...

and is the southern end of the

Hudson Highlands The Hudson Highlands are mountains on both sides of the Hudson River in New York state lying primarily in Putnam County on its east bank and Orange County on its west. They continue somewhat to the south in Westchester County and Rockland Count ...

.Sevon, W.D. (2000). Physiographic Provinces of Pennsylvania, Map 13. Pennsylvania Geologic Survey. Harrisburg, PA. The mountain is a core geographic feature throughout much of the Pennsylvania side of the Lehigh Valley. The mountain is called the Reading Prong by geologists. Unlike Blue Mountain to its north, South Mountain does not follow a straight geographic line. The mountain ranges in elevation between above sea level. The ridge is made of metamorphic rocks and

gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures a ...

, which date to the

Precambrian era The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

and range from about 570 million to 1,600 million years old. South Mountain is largely undeveloped in its northern extension due to conservation efforts and the mountain's steep slope. This makes it a beautiful backdrop to the viewpoints of the Lehigh Valley, including, at night, the city lights of Allentown. The southern end of the mountain extends west along

U.S. Route 422 U.S. Route 422 (US 422) is a long spur route of US 22 split into two segments in the U.S. states of Ohio and Pennsylvania. The western segment of US 422 runs from downtown Cleveland, Ohio, east to Ebensburg, Pennsylva ...

and the southeastern border of Berks County, providing views of Blue Mountain to the north, and Mount Penn, which comprises part of the prong and the city of

to the east. The southernmost peaks were at one time home to many exclusive sanitariums and resorts, now all defunct except for the Caron Foundation. South Mountain serves as the transmitter site for several local radio and television stations, including the independent television station

WFMZ-TV WFMZ-TV (channel 69) is an independent television station in Allentown, Pennsylvania. Locally-based Maranatha Broadcasting Company owns the station and Wilmington, Delaware–licensed MeTV affiliate WDPN-TV. Both stations share studios on Eas ...

, which maintains both its transmitter and studio facilities on the mountain, south of Allentown.

References

{{DEFAULTSORT:South Mountain ranges of Pennsylvania Landforms of Berks County, Pennsylvania Landforms of Lancaster County, Pennsylvania Landforms of Lebanon County, Pennsylvania Landforms of Lehigh County, Pennsylvania Mountains of Lehigh County, Pennsylvania