The Dr. Ruth Mirtz Collection contains nine photographs, family documents, and a family kronik all regarding the Wildermuth family.

The Photograph Series contains historic family photos and postcards. Most are related to the Mirtz, Wildermuth, and Zacher families. Writing on the back of some photos includes genealogy information and photo descriptions.

The Family Documents Series contains a certification of naturalization of Wilhelm Wildermuth, descendent and pedigree charts referencing the descendants of Wilhelm and Christianna Wildermuth, 5 burial charts and cemetery information come from the Peace Lutheran Church Cemetery, correspondence regarding the Mertz-Koenig family history and one copy of the family kronik with notes and a card regarding the kronik.