Look for pictures of assasin bugs wheel bugs. and compare the back of that one with the pictures. Assassin bugs are good because they eat other bugs. When I've watched them the only problem is that they are slow eaters.

Thanks stillanntn6b! Good suggestion!

I've never heard of an assassin bug or wheel bug. I looked them up...I don't see any pictures that look quite like the photo above though....I tried to keep looking at other photos and had to stop, it was making my skin crawl (even though I'm not really scared of bugs...there were just too many of them...)

OSU says there are 5000 kinds of beetles in Oregon. Wow, who knew?!?

The antennae are like of those of longhorn beetles and, of those listed in Oregon, the closest images I can find that look like this one's body is Rhagium inquisitor, but the antennae in photos don't generally seem as long as this guy's. Very showy antennae, which are akin to those of the Valley Elderberry Longhorn beetle, which is federally listed down here, but I don't know much of anything about them, except that it's a protected species to be on the lookout for.

Rhagium inquisitor...another interesting suggestion, thanks catspa! ...The pics online look somewhat similar but not quite. I hope this isn't it - those beetles attack trees, yikes!