Oregon does not have a statute that specifies how long the agency must keep the records so far as I can determine. However, the Oregon Department of Human Services does have a set policy on how long it will retain these records. The length of time depends on the outcome of the child protective case. You can see the details here: Child Welfare Record Retention
But the record retention policy may have been much different years ago when you were a kid, so it is possible that the records would have been destroyed much earlier back then even if the records would still be kept today if the present schedule had been in effect back then.

