You can miss the Cascades of Washington and oregon by going down the Columbia River gorge, but can hit tremendous headwinds there in spring and summer.
That's rather like saying your ride from Canada to Mexico can be flat and mostly dry if you miss the coasts of California, Oregon, and Washington and all that rain and surf and fog and traffic by turning south at Yakima.
Ride the Columbia Gorge till you get to Yakima Bend. Cross the bridge to visit the Maryhill Museum but then take off up into the mountains! You will forever regret not seeing these spectacular ranges.
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