area for use in a growing iron foundry sector. However, it was not until the realization by Andrew Carnegie, that Western Pennsylvania possessed an optimum location for a very large scale American steel sector, that this area, especially Pittsburgh, became known for the industrial specialty that characterizes it today. The region also had large glass, pottery, brickmaking, and ceramic industries, which took advantage of the coal and the sand and clay in local soils. The local glass industry produced 45 percent of the nation's output in glass by the 1860s and more than 80 percent of the output by the 1920s. 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 particular 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 equilibrium, 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 sharply downsizing 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 world at Titusville and the rise of the US petroleum industry. Another was widespread 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. The first day of deer-hunting season is a de facto unofficial holiday in much of the central and northern regions of the state, when absence from work or school is generally tolerated with no explanation necessary.