As part of the Works Progress Administration's Historical Records Survey, employees created indexes of cemetery interments using a variety of sources. While these indexes have known flaws - spelling errors are common, they provide a starting point for death records research. The Iowa WPA Graves Survey website has made the documents available online. Enter a name into their search page to search the database; as a return, you'll discover the person's name, the cemetery name, the town and county.
I'd recommend using a "soundex" search. I tried my ancestor's last name (his relatives lived in Iowa) and turned up no matches. A soundex search succeeded where a traditional search had failed. My ancestor's name had been entered with a c instead of a g. I probably could have found the same information on Find A Grave... but this a good back-up option.