I know you addressed your mail to Jean but I live in Iowa andalso am searching Harnden for a friend. I see J.W. Harnden born 1862 and died 14 August 1906 in Monroe county,Iowa is buried in Oak View cemetery, Monroe county. Also a James Clinton Harnden is buried in Monroe county - different cemetery - born 1867, died 20 November 1933 (Seceder cemetery, Monroe county).
Google the Monroe county Genealogical Society- they are an active group and an obituary for one or both of these men may be of help
Margaret