My husband and I are flying into Seattle on a Saturday in August for a cousin's wedding. We decided to stay through the following Wednesday and want to travel down to the Portland area. We know we want to see Portland itself but are curious to know about some other sites to see along the way. One thing I've read about is Columbia River Gorge - not sure if this is something you can spend a day doing? Mount St. Helens is also something I've thought about. We are very active people in our late 30's with no kids. Any advice on routes, where to stay, what to do would be greatly appreciated!