It appears that somehow he died without a death certificate. See Missouri Death Records 1910-1962, www.sos.mo.gov/archives/resources/deathcertificates/
You can contact the Historical Society of Maries County, www.rootsweb.ancestry.com/~momaries/marihiso.htm
You can contact the Maries County Court Clerk for a copy of his will/probate record.
You can do a Google search for maries county missouri cemeteries and look for him in the inventoried cemeteries. Successful Searching!