LORRIE: The Miami Valley Genealogy Researchers site has a surname list and other information. It contains some Mertz, Martz in its surname list. However, information in it ends somewhere in 1880's. So you need to go back a few generations before it can really help you. It is www.tdn-net.com/genealogy/ or go to Miami Co. OH and search around that site until you find Miami Valley Genealogical Index (MVGI). Be sure to try differnt combinations of surname spellings.