I now know they were married 2 Aug 1848, and NOT in Montgomery, Preble, or Darke Counties. I have therefore narrowed it down to Miami County where they were living in Union Twp. in 1850, and am currently searching their marriage records. I have also found the marriage record of Christopher's father Philip Young to Elizabeth Royer in 1812 in Montgomery County. Keep digging! The Young motto is "Press Through."