I'd suggest that you signup for the NWPhotographers group on facebook. They are a active group and post photos and advice for the Northwest and mostly around Puget Sound.
They also have a free website, but all the forum posting has migrated to facebook.
One of my Favorite side trips (I lived in Seattle for 35 years) is to Tillicum Village. Its located on a small island (Blake Island) and a tour boat takes you to it, which is a fantastic opportunity to use a 70-200mm lens or your 24-70mm as you cruise to the island. There is a salmon dinner and a indian show (degraded in recent years). Then, if you take the evening cruise, you will get a view of the Seattle skyline at night. Its a challenge to get good images, so plan ahead to have the right lens.
Some of the many places to visit.
Seattle Center - Space Needle is a good place to see for 100 miles.
Museum of Flight. If you like aircraft, it has a very large collection in several large buildings. Literally hundreds or thousands of exhibits. This is another challenge for the photographer, but except for the aircraft hanging in the great hall that are backlit on a bright sunny day, you can do it without flash.
Capturing those backlit aircraft will need HDR, and no tripods are allowed.
Waterfront - You can spend hours there, and the harbor tours start there.
Pike Place Market
Mount Rainer National Park - untold numbers of potential photo sites
Juanita Bay Park in Kirkland for birding photos
I'd also recommend taking a ferry to Victoria BC and taking some of the tours, or driving to Port Townsend and taking the ferry to Victoria from there. (You need a pasport or enhanced drivers license). You can take your car, but leave it behind, and take the tour busses.
Thats only a start, you could spend years.