What town do you live in? I was just in Bend, and Dufur, OR. Should hit up Tungsten Slayer he lives in the Bend area. The only offroad group I know about in the area is http://www.deschutescounty4wheelers.com/
which puts on the Groundhog Rock Crawl event, which is badass!! There is a link on their page about it. I was there two years ago, and it was cool. My buddies are trying to convince me to go again. But I will be in California with the family at that time.