This is an index of marriages. Presumably the middle initial 'R' is in error. This is the only place I have seen Bertha's maiden name... hopefully this is right.
15 Oct 1947
"Oregon, County Marriages, 1851-1975", FamilySearch (https://www.familysearch.org/ark:/61903/1:1:CMM6-CGT2 : Wed Apr 23 22:20:46 UTC 2025), Entry for Bertha L Borek and William R Volpalensky, 15 Oct.