DH and I have 1 week in Seattle at the end of July/early August 2017. We have been to Seattle before and want to explore some Washington Wine regions in Washington, e.g. Walla Walla. We will have a car and are open to other Wine region areas in Washington. We will spend the first night in Seattle and fly out very late on the return. We are considering going to one of the parks - would like to do some hiking. Recommendations for parks and itinerary? I realize that Walla Walla is 4.5 hours driving time.
Thank you!

If you mean you want to hike in Walla Walla, realize it will be really hot. 90+.

Unless part of this is to see the north cascades NP, I would fly from Seattle to Walla Walla and rent a car in Walla Walla if you want to tour the wineries. But you could also just fly to Walla Walla and stay in the Marcus Whitman and go to all of the tasting rooms downtown.

I think I need a better idea of what you want to do...

Several options come to mind:

1. Consider a loop to the Yakima Valley, returning via Mount Rainier, or v.v., something like this: https://goo.gl/maps/1haVXYVaVY72 (Note I've used Toppenish for the turn-around point, but that's really a placeholder; you should look at Yakima Valley winery options for more specific locations.)

2. Look at the Yakima Valley combined with Maryhill and the Hood River Valley - numerous wineries, plus Mount Hood and the Columbia River Gorge. There are up-and-coming wineries in the valley, along with orchards, lots of craft beer, umpteen hiking and adventure options, and many things to occupy several days. https://goo.gl/maps/fevAXFA5XFT2

3. Walla Walla and the Wallowa mountains. The Wallowa mountains in NE Oregon are under the radar for many people, but the landscapes are fantastic and relatively easy to combine with winery-hopping in the Walla Walla area. Joseph OR is a terrific town set in stunning surroundings. https://goo.gl/maps/TUX5YsJzuwT2

Super recommendations, Gardyloo! Thank you. Walla Walla has been on our radar for some time, and I've read that it's more scenic than Yakima. Will research Wallowa - wounds great. We are interested in exploring winery area for a few days, to take in some of the sites, and to do a little hiking. Marvelousmouse, thanks for the weather report, we will be prepared.. we were not planning to hike in Walla Walla, but in one of the many parks. I have not done enough research on places to hike, nor places to stay. Will be back in touch!

In my opinion, Washington's most scenic wine district is on Lake Chelan. Driving through it in the Manson region, one has sweeping views of the lake and the surrounding mountains: http://www.lakechelanwinevalley.com

There is also a wine district in the beautiful Columbia River gorge: http://www.columbiagorgewine.com

A possible round-trip route taking in four of Washington's wine regions and a great National Park would be Seattle - Chelan - Walla Walla - Columbia River - Yakima - Mt. Rainier - Seattle.

This routing includes Stevens Pass (Highway 2) and Chinook Pass (Highway 410) or White Pass (Highway 12).

HTtY

PS The Wallowa Mountains are beautiful. It's too bad it takes a long in-and-out detour to visit them. If you go there, you are likely to wonder how many Oregonians have ever been to that remote part of the state.