My ancestor was also with the 5th U.S.V. from camp Douglas til he deserted in August '65 at Cottonwood,Crossing,Kansas

Here is a bit of info.:

Summer of 1865 (Companies "I" & "K" stationed on the Julesburg-Denver trail)

General Sherman had made up his mind to mustered out the 5th Regiment and return the "Galvanized Yankees" to civilian
life before Winter of 1866

General Sherman reached the decision on September 30,1866 at Fort Lyon; where Companies "H",'I", and "K" of the 5th Regiment
U.S. Vols. were garrisoned in unfloored,flat-roofed buildings subject to flooding. Sherman found them unfit for human habitation.

info. taken from "The Galvanized Yankees" Dee Alexander Brown;1963

Try GOOGLE BOOK for more information:

"5th/Fifth Regiment U.S. Volunteers"/"Infantry" /"Kansas" /"1865"/ "1866"

Regards,
-JOHN