Thank you for the awesome replies!

I didn't even think of Hood River, but it does sound great. Will definitely consider it! Mt Hood sounds great, especially if its more accessible than Rainier!

Is the Enchanted Forest in Salem worth the time?

Well, my wife and I love mountains and greenery. Not as big a fan of the coast, but we do love big cliffs too! So we could probably do a combination. As for the 3 year old.. do 3 year olds enjoy scenery? (honest question.) Right now my son likes diggers, and cranes, and fire engines, and airplanes.. maybe he'll enjoy a waterfall but I don't think he'll notice mountains or trees