Some surnames connected to Gierach / Gerach in the area's German-American papers are Seeger Bartelt Berndt Garbisch Hinz Wedig.
[I'm not a relative, nor researching these families]
Spelling variations like Gerach and Gieratz should probably be considered when looking through any index. For instance, in the German papers, an O. H. Gerach, from Neustadt a. Haardt (Rhein-Pfalz, Bayern) was looking for his aunt Mrs. E. (Gerach) Petersen, from Queichheim, Rheinpfalz, or her kids Fanny & Lizzy. They were last known to be in Milwaukee, WI
"Milwaukee's German Newspapers; an index of death notices and related items" (covering 1844-1950). It's never really been just about "obituaries" (most of which are really death notices ;-)https://encore.mcfls.org/iii/encore/record/C__Rb3327521