East of the Cascades has little Pacific influence. It’s basically high desert, very dry and can get extremely cold/snow etc.
I've lived east of the Cascades for 58 years, worked as a scientist in an atmospherics and geophysics lab here, and yes we do have considerable Pacific influence in weather -- including right at this moment when we're having drops of Pacific ocean water dropped on us at the rate of 0.05 inch/hour. If you've ever looked at a wave cloud on top of Mt. Rainier you're looking at Pacific influence go right over the tops of the Cascades. In addition, many of our storms come up through the Columbia Gorge and then spread over the flatlands. The only time we're lacking Pacific influence is during an Arctic incursion in the winter -- but Idaho gets it much worse.
It’s basically high desert
I'm east of the Cascades and the elevation at my house is 387 feet MSL.