I do not see a town of Shannon in Colorado.There is a "Shannon Last Chance Mine" in Chaffee Co, CO, south of Buena Vista, CO.
There is a town of Shannon in Clay Co, TX, and Eminence is in Chambers Co, TX.
Have you looked for George on any census records?If you do not have access to the new set of 56 CDs for the 1880 census, there are several people on the TX forum that have their own set and will do lookups.It contains an EVERYNAME list so you can search for wife, children, or anyone living in the household.Post a query, put something the subject box to catch their attention, "Need 1880 census lookup."If you have any additional info on George, such as location of birth, approximate birth year etc.It will help to narrow the search, although Turpin probably isn't all that common.At the time of the 1880 census did he have a wife, or children?
Once you have info from 1880 then you can go looking for the 1900 census.You might check the Platte Co, MO GenWeb site, some GenWeb counties are not only putting their cemeteries online, but some are doing the census -- just for their county.See if they've done the 1900.If not on the county site, be sure to check the archived section of the GenWeb Project, too.Post a query on the county site, someone may recognize the Turpin family name.Happy Hunting.