Georges Gulch as a place name or mining camp didn't make it onto any of the Colorado maps of the Civil War Colorado Territory period that we have found in our research for our Colorado Places listing at
http://www.rootsweb.com/~coyuma/city/index.htmlThere are at least two Georges Gulches on the modern map as area names, one in Routt County and the other in Larimer County. If one of these is correct for your gg gfather, it is most likely the one just southwest of the old Virgina Dale stage station in Larimer County.
Lee Zion