I do not know where my husband filed for divorce it was between 1972 - 1974. Can you help me since I have no idea what county.

Sydney

Do you know the state ? Often you can contact state records. But why don't you know the area, where ( what city was he living in) that will be the location

He was living in Northern California, but does not remember the county... it has been 39 years ago.

The county will have to be the county where for the city he lived in, so what town or city was it living at.

http://www.cdph.ca.gov/certlic/birthdeathmar/Pages/CertifiedCopiesofMarriageandDivorceRecords.aspx