Jeff's route is pretty good, but be cautious in the Pete's Mountain area:
Mountain Rd has no shoulders and no bike lanes; no posted speed limit, either, which means people go anywhere from 45 to 65 mph (depending on their age). Basic speed law in Clackamas Co is 45.
Turner also has no shoulders and no bike lanes; it doesn't even have any paint! There are a lot of blind corners on Mountain and Turner, and if you're on this road during a school day, watch out for school buses.
Borland has no shoulders and no bike lanes; it's posted 45mph in places, then goes down to 35 and 25 once you get into Willamette. Actually, now that I think about it, bike lanes appears shortly after it changes to 35... but disappear once you get out the other side of Willamette. Willamette Falls Drive (which Borland turns into in Willamette proper) becomes the default surface-street for people avoiding bad traffic on 205, just FYI on that.
Otherwise, it's a beautiful route!