More on Great Appalachian Valley from Fact Monster:

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• Holston - Holston Holston, river, c.120 mi (190 km) long, formed by the uniting of its northern and southern ...
• Pennsylvania: Geography - Geography The Great Lakes Plain meets the Appalachian Plateau in the extreme northwestern part of ...
• Pennsylvania: Economy - Economy Iron smelting, made possible by abundant supplies of ore and of hardwoods for the furnaces, ...
• Appalachian Mountains - Appalachian Mountains Appalachian Mountains , mountain system of E North America, extending in a ...

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