Seattle - I would suggest staying on Bainbridge Island or somewher on Kitsap Peninsula and then go to the Olympic National Park. Amazing trails and just gorgeous. Lots of trails. You can read the Olympic Peninsula within 40 minutes from Bainbridge (usually les). There are also trails in Fay Bainbridge State Park and of course a 2 mile hike in the Bloedel Reserve. There is also the Great Forest Park (it's not that big) that has small hiking). Taking the ferry across to Seattle and then doing Mt. Si is a nice way to break up a day as well.