[EC900]

Are you saying you are now a OR resident and the last time your car was registered was in CA?
When the last registration completed? Moved out of state and let the last plate Reg expire?

I think the inquiry outdates when the CA DMV transitioned from paper to computer records.
Older reg might be on microfiche and not included in computer database. This is very common.
Did you inquiry in-person, by telephone or by writing.
FYI - there is an online portal that costs $ for a record search, especially useful of original owners, limited info available and released for non-owners of vehicles.
Theres a lot of new generation clerks at the DMV that either don’t know old files exist, don’t realize someone in the department does, or doesn't want or know how to access old records or even ask or refer someone to your inquiry.

You being the owner of record should be able to get a duplicate title regardless of where the car is parked, albeit w/o a CA address, plates can’t be issued. Getting the right person to understand and capable is the task.

Yes, CHP can run a title search but be advised, not for matters not related to the scope of their investigations. Some of the courtesies offered in the past have made these sort of inquiries difficult if not altogether forbidden due to civil matters, personal information protections usually involving property settlements. You might get an “ok, there’s a title #xxxx on file” but that’s it.