I am studying the Cowger / Gauger family and related families and am glad to exchange information.
The Cowger surname seems to originate with the family of John Conrad and Anna Barbara (Probst) Cowger, who moved from New Jersey to what is now Pendleton County, West Virginia, in about 1760. John, originally Johann Conrath Gauger, immigrated from Germany in 1736 (probably from the area around Stuttgart), landing in Philadelphia. His name and the name of Georg Nicholas Gauger, probably a brother, can be seen on the ship's list at www.mcn.org/2/noel/ShipsList.jpg.
Currently I am researching the descendants of Henry Jacob and Susanna Christina (Harper) Cowger, who were both born in Pendleton County and married there in 1885. Henry was a great-great-grandson of John Conrad Cowger. In 1736, after the birth of Henry and Susanna's first child in Moorefield, Hardy County, they moved west, eventually settling in Monterey County, California, where their other four children were born.