Currently you can find PDFs of the 1955-1967 and 1995-2009 ORS at the Oregon Legislature’s website. Soon, the 1969-1993 superseded ORSs will be there, too. (Look under: “Selected Archives of the Oregon Revised Statutes.”)
The Washington County Law Library has been scanning these pre-1995 ORSs for the Legislature and they have been making those images available to everyone from their website. We have scanned through 1989 (and started 1991), but for a publicly-hosted set of these superseded statutes for the years 1967-1993, you need to be patient.
We have been told that the Legislature is in the middle of a website redesign project and won’t be able to publish the 1967-1993 superseded ORSs until October. (We wish them luck and lots of pizza for sustenance! A redesign is lots of work, lots of fun work (at least for librarians, website designers, and content strategists), but it is a mega-ton of work from start to finish, especially on the scale of a state legislature’s website).