Cycle Oregon did it 2 years ago. You *might* find the map on their site or on cyclingsite somewhere. As I recall, through Hood River followed Hwy 30 (State St, Oak St, Cascade Ave), and then got onto I-84 westbound. Exited at Viento for lunch, then back on Wyeth or something like that. Amazingly steep climb
up, then down and through Cascade Locks, which is longer than you'd think it is. Then west on the bikepath out of Cascade Locks, jumping onto I-84 westbound before you run out of bike path (about 4 miles; you'll cross a bridge and the trail ends. Go back and hop onto the freeway shoulder; there are several places where you can do that. Get off at Warrendale, then follow the Scenic Highway all the way into Troutdale. You can probably work it out from there.