It is irrelevant that you have a Washington license, and Oregon does share information with Washington, so you want to try to keep this off your record and save money in insurance while keeping your driving record clean.
Every state handles these differently. Going "only 85" - 20 over the limit - is not going to be a good defense. What you need is someone who can present your best defenses, and unfortunately you provide the citation but nothing else. An experienced traffic attorney in Oregon will be able to look at items beyond the citation you received so that technical and substantive issues can be explored on your behalf. Contact an Oregon attorney in the area of Oregon in which you were cited.
This answer is given merely for informational purposes and does not create an attorney-client relationship. For specific advice, contact an attorney in your state to see if working together makes sense.
Find a lawyer in the jurisdiction that you can contest the speeding ticket and see if you have any defense. If you were going in excess of 20 mph over the speed limit you are lucky you were not charged criminally with reckless driving. But if you do this pro se, do not say I may have been speeding, but only 20 over not 25.
If you are in Massachusetts, my answering of your question does not constitute an attorney/client relationship and are for informational purposes only. If you wish to contact me to discuss your question further I offer a 30 minute free consultation and can be reached at 413-522-6263.
If you are not in Massachusetts I am not giving you legal advice as I am not licensed in your state and my comments should be viewed as for informational purposes only.