Long story short, we have Montana to thank for the way our wines taste. Around 12,000 years ago, something called the Cordilleran Ice Sheet moved south from Canada into what's now the USA. This dammed the Clark Fork River, which created a ridiculously large lake known as Glacial Lake Missoula. Of course, the ice didn't last - it failed every so often, and when it did, the whole lake emptied in a series of mind-blowingly large flash floods that devastated a large area of present day Washington state.
This weekend,
So, even if Washington state does have the perfect climate for wine, it's the boringness of its soils combined with their uniform geographic distribution that means you'll probably never experience a truly profound wine from the state. Yes, we do good stuff up here - a Yakima Cellars Elephant Mountain syrah will put a huge grin on your face - but when it comes to terroir, we're sorely lacking.
Oh, and Oregon? You're not off the hook either. Thanks to something called the Wallula Gap, the flood waters slowed down and backed up for a bit, but eventually all of those catastrophic floods wound up depositing much the same kind of debris in the Willamette valley, so your soils aren't anything special either. However, your weather is definitely cooler and wetter, so it's no wonder your riesling and pinot noir are better than ours. :)