I don't have any advice about Oregon, but I did get a chuckle out of your comment about license plates.
A Spence-length story:
When I first moved to State College from Texas in 2005, I (in my typically lazy fashion) failed to get my plates swapped out for over a year. Of course, during that year I probably fished Spring Creek an average of 5 days a week.
Many times that year, I'd run into other fishermen, start chatting, and at some point in the conversation you'd see the light bulb go off in their heads and they'd blurt out: "So YOU'RE the guy with the Texas plates! I see that car all up and down the creek, and I've been wondering for a while who that was, and how that guy had so much time to be fishing up here! Everywhere I turn I see that car..."
There was one guy in particular who actually lived right there on the creek near one of the spots I often parked, and who I could tell kinda had a problem with me because of the Texas plates (I was clearly an interloper catching fish quite literally in his front yard). He'd often stroll down to the creek as I was getting back to my car and ask me how I did. My first response was always my usual response when posed that question: "A few, here and there."
He'd look at me with a sideways glance and follow up with: "How many is 'a few', exactly?"
I knew I wasn't telling him anything he didn't already know about the creek, so I'd always be honest with him. Usually, my next answer was: "I'm not sure exactly, but probably around 35-40. A few nice ones, too."
This would always make him visibly frustrated - he was a pretty polite guy, so wouldn't say anything, but you could tell by the look on his face he wasn't catching nearly that many, and it kinda pissed him off that some punk-ass kid from TEXAS of all places was catching all of those fish in his "own back yard".
So one day I parked by his house, but fished a much longer stretch of water than what I'd ever fished from that parking spot before. The water wasn't great, but I'm glad I checked it out. I finally emerge from the creek a couple of miles from my car and start the long walk back down the road to my car. Just as I'm getting to the road this guy pulls up in his car, and I think maybe he's going to offer me a ride back to my car (since I'm parked right in front of his house).
He immediately starts off with: "So, you did you do today?"
ME: "A few, here and there."
HIM (with an even more suspicious look than usual): "How many is a few?"
ME: "Well, it was a really slow day; I think I only caught about a dozen."
HIM: "I fished all day, and I only caught one. I had to stop and see how you did, because if you had told me you had caught 30 again today, then I would have known you were full of shit all along!"
Then he drives off. Never saw the guy again (though I fished in front of his house many times after that).