Pennsylvania has a long and rich tradition of mining especially for anthracite and bituminous coal as well as iron. What is not generally known however is the state is also produced a considerable amount of gold.
The eastern part of the state is covered with crystalline rocks producing gold lodes as well as placer gold. This gold weathers out of the crystalline rocks and is collected in the rivers and streams of eastern Pennsylvania. This is not the only source of gold however, in the western part of the state if the last glacier failed to get into Pennsylvania there are several that probably did during the past million years.
Although the eastern part of the state is mostly covered with crystalline rocks that produce gold as low gold that weather is out and becomes placer gold that collects in the rivers and streams found in eastern Pennsylvania. Far from being the only part of the state containing placer gold the rest of the state has been glaciated one or more times. If the last glacier missed getting into Pennsylvania there are any number of preceding glaciers that may have.
One of the places where gold has been found is along the Susquehanna River where it has been found as both nuggets and flakes of gold. Generally Wyoming County has been a good place to look for gold as well as in the surrounding counties. In York County placer gold is associated with the deposits of diabase that make up the tops of many ridges. The action of weathering releases the gold from bedrock allowing it to migrate downhill into the streams and rivers in the area.
Gold is often found associated with granular magnetite such as that found in Cornwall Pennsylvania near the iron mines. It should be noted that a lot of the gold found in Pennsylvania has been associated with the iron mining industry. This is not the only area where gold is associated with iron. The gold deposits of Nova Scotia, Canada are often associated with granular magnetite.
The best way to find out where the gold is in Pennsylvania is to research old newspapers and town histories. The state only keeps track of commercial mining operations and not that of individual prospectors. Old newspapers are often the source of stories about where one of the local citizens has found gold in their town.