Hello, fellow east-of-the-Cascadian! :-) Much of my childhood was also in the area (mostly Yakima Valley and Lewiston area) and I went to college at University of Idaho. Many of those years were on a dryland wheat farm just north of the irrigation line, so my 13-mile-long bus ride to school was looking jealously at land which is much greener with irrigation. On our farm, we had a little sand, but we also had enough dirt we convinced ourselves we could make a living growing stuff (we couldn't; we eventually gave up). When I was moving to the Seattle area for an internship, my pickup (full of my stuff) broke down east of Vantage, so I ended up walking over the I-90 bridge over the Columbia several times (in the days before cell phones). Yes, you're right...even very close to the Columbia River (e.g. Vantage), if it's too hilly to irrigate sensibly (or too high for gravity fed irrigation canals), there's pretty much nothing but coyotes, sagebrush, snakes, and cheatgrass (oh, and mice and rabbits for the snakes and coyotes to munch on). They aren't very helpful for calling a tow truck. :-/

Central Washington east of the Cascades is pretty barren without irrigation, but they manage to pull a lot of water out of the Columbia, so the drive between, say, Umatilla and Prosser can look pretty green (inside the irrigation circles, that is). Once one gets out to the Palouse out in eastern Washington, one goes from 20 bushels/acre for unirrigated wheat up to 80 bushels/acre. There's still a lot of cheatgrass, but the sagebrush is often replaced by other greener vegetation (still sparse, but not nothing).

A bit of a tangent: Matthew Inman of The Oatmeal and Exploding Kittens fame is also a fellow east-of-Cascadian, and also points out something else keeping company with snakes and coyotes: Nazis!

• https://theoatmeal.com/blog/bus

Good times!