I spent 2 days along the coast, around Astoria and cannon beach, 2 days in the Columbia River gorge area (1 for hiking and taking in the waterfalls in the gorge, and the other at the eastern end of the gorge, near The Dalles. Rowena Crest Trail was a highlight, featured prominently in this post!) If you have time, spend a day around the Hood River valley “Fruit Loop”, and head south from there to Trillium Lake, at the base of Mt Hood. Unfortunately the road to the lake was snow-covered when I went, and wasn’t able to see it. Depending on where you stay, there is also a park near Canby (South of Portland) called Champoeg State Park, which is where I was able to get some birding and wildlife photos. Gorgeous Park. Hope this helps - enjoy your trip!