Toy Man!
So you're the one I see on highway 26 every once in awhile! I live in Beaverton, but I commute to PDX every day so I see you every once in awhile. The license plate is a dead giveaway.
Anyway, back to the question on the table:
I've had good luck playing around in Brown's camp, and although it ain't exactly hard core it's fun. Maybe I'm missing the more difficult trails there ? ?
I do know of some private trails outside Portland, mostly some old logging roads. There seem to be alot of those around. The most fun I've had has been in trails in the Willamette and Deschutes national forests. They seem to have the least amount of overgrown trees/pin striping brush, and they're all BLM land so you can get a permit to go wheeling.