Search Builder (Search menu » Search Builder) gives exclusion options on pretty much any field. See the attached screenshot. You would of course have to add additional criteria relating to who constitutes a donor.
You can use custom search 'Include / Exclude Search' (CiviCRM >> Search >> Custom Searches >> Include / Exclude Search)
Create a smart group of donor who stay in CA
Create a smart group of donor who stay in Bakersfield, CA
Use Include / Exclude Search, to search contact in group #1 and exclude from #2