Did Frank and Bertha divorce? 1940 Spokane, Spokane WA Bertha MEAD 64 IN; resided 1935 St Paul MN; maid If right person she remained in Spokane and d 5-12-1965. 1940 Frank is in St Paul, alone.
Chas/Charlotte RASCHKE resided 1900 Beadle Co SD I know you didn't request info on this family, but knowing Bertha's name would'be been helpful to volunteers in trying to track Frank. Looks like you apparently have all you need on this family after viewing their memorials on findagrave.
What does Frank's DC/obit have to say re: his parents? Wish you success.