Marcellus Shale Maps:  Below are a few maps outlining the Marcellus Shale formation.  We for more details visit http://oilshalegas.com/marcellusshale.html

Also below is a map of the United States pipeline system.  As you can see, there are not many pipelines going through the northwest section of Pennsylvania ( PA ) which further delays development of the Marcellus Shale.