Find lots of great information, free maps and elevation diagrams here at rideoregonride.com. Another great resource to get routes on your own GPS and tour on your own - Check out Ride with GPS. Still more ideas! Here are a couple of my favorites:
https://stateparks.oregon.gov/index.cfm?do=things-to-do.scenic-bikeways#CoveredBridges
https://traveloregon.com/things-to-do/outdoor-recreation/bicycling/willamette-valley-scenic-bikeway/
