At this point you take an access ramp to join US 90 West and cross the bridge to Vantage (good espresso stand there!), and from here to Seattle it's all divided highway. And from here on the scenery gets more and more spectacular. If you had started in Spokane, you would have driven to this point on I-90 West.

Ellensburg is used by most travelers as a gas and food stop, but if you have the time to explore, it's also the home of Central Washington University and has some charming neighborhoods.