Long recognized as a powerhouse of American industry, Western Pennsylvania is a large geophyisical and socio-economic entity within the state of Pennsylvania, roughly the western third of the state. It encompasses that portion of the state to the west of the Appalachian divide and included within the Mississippi drainage system of rivers. It is centered around the large city of Pittsburgh.

The largest rivers in this area are the Allegheny River, which flows southward from the New York border, and the Monongahela River, which flows northward from West Virginia. These two rivers meet at the city center of Pittsburgh and join to form the Ohio River, which from that point flows an additional 981 miles southwest to the Mississippi River. The juncture of the Allegheny and Monongahela was historically regarded as strategic and the gateway to the interior of the continent from the east. At various times this junture has been called the Forks of the Ohio, Fort Duquesne, Fort Pitt, the Golden Triangle, and today, at its apex, Point State Park. Incredibly, after several decades of border war and 150 years of high-rent city-center urbanization, the original 1764 blockhouse from Fort Pitt still stands here and is one of the oldest buildings in the region. Other notable rivers are the Youghiogheny River, flowing north from West Virginia and western Maryland and which was the early route of penetration into Western Pennsylvania, and the small Oil Creek in the north, where slicks gave an indication of petroleum reserves and in whose watershead the first oil well in the USA was drilled.

The highest point in Western Pennsylvania is Mount Davis at 3,213 feet, where the Appalachian Mountains enter Pennsylvania from the south. To the west and north of this point lies the Allegheny Plateau, a dissected plateau so eroded that it appears to be an interminable series of high hills and steep valleys. The peaks in the area are among the lowest in the East Coast highlands, but what they lack in height they make up in wide extent of land covered, which forms a vast formible barrier for mile upon mile to overland travel from the coast.

Western Pennsylvania is distinctive from the rest of the state due to several important and complex factors, such as:

• The intital difficulty of transportation access from the east across miles of seemingly endless parallel ridges of the Appalachian Mountains, and then the broken hills and valleys of the Allegheny Plateau. Indeed the intial method of access was to go out of Pennsylvania altogether, follow the Potomac River northwest through Maryland and Virginia, and then re-enter the state in its southwest corner. Various methods of more direct transport were later tried, including, weirdly, a canal system over the Appalachians and then, later, extension of the railroad system west. Perhaps the best know transportation innovation to simplify access to this area is the famous Pennsylvania Turnpike.

• The initial problem of economic marketing of a limited number of goods that could stand such high freight costs. The insentivity of the new US Federal Government to the marketing problems in the west led to the Whiskey Rebellion in Western Pennsylvania, an event which seriously challenged the political viability of the new American nation. Later marketing arrangements turned to access via the Ohio River, with Pittsburgh a barge and steamboat center of the mid-continent. Today, Pittsburgh is still strongly oriented to the rivers; the port of Pittsburgh ranks No. 13 by tonnage in the USA and even surpasses the Port of Philadelphia in tonnage, thanks to the heavy shipping of bulk coal by barge inland on the rivers ( Source: US Corps of Engineers, Waterborne Commerce by Tonnage, 2002). Locally, a system of agriculture arose suitable to Western Pennsylvania's rugged terrain, emphasizing animal husbandry and dairying but with few exportable vegetable crops. The search for some sort of exportable agricultural specialty perhaps also encouraged the rise of the sauce industry and its first location at Sharpsburg in what was later to become the large H.J. Heinz Company.

• The search for exploitable resources first resulted with the development of huge soft coal deposits in the area for use in an growing iron foundry sector. It was not until the realization by Andrew Carnegie, however, that Western Pennsylvania possesed an optimum location for a very large scale American steel sector that this area, and especially Pittsburgh, became known for the industrial specialty that characterizes them today. The rise and subsequent decline of the American steel industry at Pittsburgh introduces a host of complex economic concepts necessary to understand why that particular activity centered in this particlar place, including the notions of classical Weberian location analysis for more than one input, the Pittsburgh Plus system for maintaining advantageous freight costs to ship to the market, vertical integration and supply innovations such as the development of the Mesabi Range, the ore freighter as a transport vehicle, and the construction of the Soo Locks. Other necessary economic concepts for description could well include economies of scale, diseconomies of scale, monopoly ( or cartel) price equlibrium, and " dumping". Labor relations problems historically were frequent in the earlier steel sector, and mention should be made of the United Steel Workers of America, as well as the contemporary issue of " legacy costs" arising from heavy entitlements to a large retired labor force after sharly downziing to today's level of employment.

• Other exploitable resources in Western Pennsylvania were also distinct. One was the drilling of the first oil well in the USA at Titusville and the rise of the US petroleum industry. Another was wide-spread deforestation of the outlying areas and their subsequent reforestation under Gifford Pinchot, who instituted the first large scale government sponsored timber management effort in the USA. During this time of intensive exploitation of forests a whole new sector, the wood chemistry industry, appeared and then later vanished. Finally, mention should also be made of management in the forested areas of a large animal population which supports the famous " Pennsylvania deer-hunting" cultural ethos.

• After the decline if the American steel industry in Western Pennylvania, a partial renaissance ocurred in the development of cultural institutions and abatement of pollution. The effects of this increase in liveability are particularly apparent in the Golden Triangle district of downtown Pittsburgh, which at one point had been plagued with so much industrial haze that drvers used their headlights in mid-day. However, this social improvement has not always been accompanied by a serious plan of regional economic development to assess what, precisely, should fill the income void after the departure of steel. In addition, the city of Pittsburgh continues to become de-populated and has recently been put under state supervision of its finances.

• Culturally, the distinctiveness of Western Pennsylvania is underlined by the existence of a unique Pittsburgh English local dialect, sometimes affectionately termed the "yinzer" dialect, due to its use of the term "yins" as the plural form of "you".

• Near Sharpsburg, Somerset County, is the site of the crash of United Airlines Flight 93, the " Let's Roll" flight which occurred on 9/11 after passengers attempted to overpower the plane's hijackers. The site is an informal patriotic shrine with many hand-made momentos voluntarily gracing the area. There is a movemont to add the site to the National Park System. It is a startling coincidence that the Sharpsburg site is comparatively close to the other centuries-earlier locations of military engagements in Western Pennsylvania, such as Fort Duquesne and the area of the Whiskey Rebellion. This can in part be explained by the fact that all these locations were on a strategic, direct tranport route from Washington, D.C to the west.

• Although not strictly within the limits of this area, North-western Pennsylvania, together with its "stove pipe" extension to Lake Erie (see Erie Triangle), can well be included with a brief description, given the function of the city of Erie as a port for the western part of the state. In the Erie region mention should be made of its dinctinct and fertile agriculture centered around grapes and other fruit, the narrow band of usually moderating climate influence from the Great Lake, and the existence of small commercial fresh-water fisheries with a catch of yellow perch and walleye.