Here are two web sites pertaining mainly to families of western Pennsylvania. Both are recently updated from my 1999 book: Clifford, H. F.: The Oil Creek Flemings of Venango County, Pennsylvania, with related families. One web site deals with the surname Fleming, starting with John and Sarah (Reed) Fleming of Fayette County, Pennsylvania, and follows the descendants of their six sons (Andrew, Daniel, Samuel, James, Edward and Ezekiel) through several generations. Many of the Fleming sons’ descendants were located in Oil Creek Township, Venango County, Pennsylvania. A related branch, Lytles, moved to Mt. Vernon, Ohio. The web site includes a section on “Oil and our Oil Creek ancestors.”
The other web site deals with the related families McClintocks and Culbertsons, starting with the known founders in eastern Pennsylvania, Francis McClintock and Patrick Culbertson. Many of their descendants located in Venango and Crawford Counties, Pennsylvania, especially descendants of brothers Hamilton and Francis McClintock of Cornplanter Township, Venango County, and Robert and Jane (Culbertson) McFate of Venango and Crawford Counties, Pennsylvania.