OREGON. WE LIKE IT HERE. YOU MIGHT TOO.
Waterfalls are nice, if you like that sort of thing. The Columbia River Gorge is filled with them, from Crown Point to the Fruit Loop, all just a short drive from Portland. Multnomah Falls, Horsetail, Bridal Veil, Pony Tail. You could do worse as sightseeing goes, which might be why congress named the Gorge the largest national scenic area in America.
But if you get tired of watching waterfalls, you can still visit the small towns to see their famous craft breweries turn some of that water into the best handmade beers on earth. Just make sure you get the windsurfing, kite boarding, sailing, hiking and biking out of the way first.