Geography of Pennsylvania

Pennsylvania's nickname "The Keystone State" is quite apt, as the state forms a geographic bridge both between the Northeastern states and the Southern states, and between the Atlantic seaboard and the Midwest. It is bordered on the north and northeast by New York, on the east, across the Delaware River by New Jersey, on the south by Delaware, Maryland, and West Virginia, on the west by Ohio, and on the northwest by Lake Erie. The Delaware, Susquehanna, Monongahela, Allegheny, and Ohio Rivers are the major rivers of the state. The Youghiogheny River and Oil Creek are smaller rivers which have played an important role in the development of the state. The capital is Harrisburg, Pennsylvania.

Pennsylvania is 180 miles (290 km) north to south and 310 miles (500 km) east to west. The total land area is 44,817 square miles (119,283 km²), 739,200 acres (2,990 km²) of which are bodies of water. It is the 33rd largest state in the United States. The highest point of 3,213 feet (979 m) above sea level is at Mount Davis. Its lowest point is at sea level on the Delaware River. Pennsylvania is in the Eastern time zone.

The western third of the state can be considered a separate large geophysical unit, distinctive enough that itmay best be described on its own. Several important, complex factors set Western Pennsylvania apart in many respects from the east, such as the initial difficulty of access across the mountains, rivers orientated to the Mississippi drainage system, and above all, the complex economics involved in the rise and decline of the American steel industry centered around Pittsburgh. Other factors, such as a markedly different style of agriculture, the rise of the oil industry, timber exploitation and the old wood chemical industry, and even, in linguistics, the local dialect, all make this large area sometimes seem a virtual "state within a state".

Pennsylvania is bisected diagonally by ridges of the Appalachian Mountains from southwest to northeast. To the northwest of the folded mountains is the Allegheny Plateau, which continues into southwestern and south central New York. This plateau is so dissected by valleys that it also seems mountainous. The Plateau is underlain by sedimentary rocks of Mississippian and Pennsylvanian age, which bear abundant fossils, as well as natural gas and petroleum. In 1859 near Titusville Edwin L. Drake drilled the first oil well in the USA into these sediments. Similar rock layers also contain coal to the south and east of the oil and gas deposits. In the metamorphic (folded) belt, anthracite (hard coal) is mined near Wilkes-Barre and Hazleton. These fossil fuels have been an important resource to Pennsylvania. Timber and dairy farming are also sources of livelihood for midstate and western Pennsylvania. Along the shore of Lake Erie in the far northwest are orchards and vineyards.

2006 Pennsylvania license plate.Pennsylvania has 89 miles of shoreline along the Delaware River estuary but is a landlocked state with no coastline bordering the Atlantic Ocean. (The difference between the coast (the shore of an ocean) and the shore (a protected bay, bayou, estuary, or sound) and how these concepts are measured is explained at length in an extended footnote under "Miscellaneous" in the article on New Hampshire.) Pennsylvania is the only truly landlocked state of the original thirteen states, although Connecticut, located on the Long Island Sound, also has no actual coastline.

Pennsylvania has one of the largest seaports in the U.S. on its narrow shore, the Port of Philadelphia. In the west the Port of Pittsburgh is also very large and even exceeds Philadelphia in rank by annual tonnage, due to the large volume of bulk coal shipped by barge down the Ohio River. Chester, downstream from Philadelphia, and Erie, the Great Lakes outlet on Lake Erie in the Erie Triangle, are smaller but still important ports.

Pennsylvania has been the site of some of the most horrendous ecological disasters experienced in the USA. In 1889 the South Fork Dam, impounding a recreational mountain lake for sportsmen, burst after a heavy rain and destroyed the downstream factory town of Johnstown, killing over 2,200 inhabitants in the notorious Johnstown Flood (the town was later rebuilt and is a reasonably large community today in the central mountains). In 1961 an exposed seam of coal at Centralia, Pennsylvania caught fire and forced eventually almost the entire community to abandon their settlement; the coal fire is still burning today and is estimated to last 100 years more. Finally, in 1979 the Three Mile Island Nuclear Power Incident near the state capital of Harrisburg, while not as destructive to the community, nevertheless cost close to $1 billion to clean up and changed the national public perception of nuclear power to a much less favorable viewpoint.