I got land in Okanogan last Summer Solstice. You can check out my thread about it here
https://permies.com/t/56342/Moving-Okanogan-homestead-land-pics#533576
Some things to consider, check into what the pros and cons are for different counties each have good and bad. For example Ferry Co has an off grid system through the PUD. Where they will come set up an off grid system for you, and you rent to own it. Once you pay it off it is yours. But the bad part is property taxes tend to be a bit higher in Ferry Co.
Something else to look at is access, a lot of the roads in the northern part of the region east west can close in the winter due to snow. The main routes of north and south though stay open. Also look at potential flood problems and bridges that might get washed out when looking at access.
I would highly suggest spending time on
http://www.desertlakerealty.com/ looking at properties. If your not already. Just to get a general idea of prices, areas, what to sells and what doesn't, etc... The best deals will almost always be for sale by owner stuff, but if your coming out of state that can be a struggle. I was in Western WA, and the 6 hr drive from Seattle to Tonnasket didn't make for great land searching.
Something to note, if you don't like "hippies" you might want to know Tonnasket has a couple festivals every year that bring in a lot of them. A spring one and a fall one. Or if you do like "hippies" then this might be something positive for the region.
*edit to add this paragraph ( I had forgotten to mention it last night)
Something to note about the Spokane area, a lot of the white supremacists who had been in Idaho moved over to the Spokane area about a decade ago when one of their top leaders went to prison. This sort of drove them out of Idaho, but they just kind of congregated in Spokane instead which had already had a bit of a white supremacist presence since the 80's to gather around. You might have heard about the Martian Luther King parade pipe bombing incident in 2011? Thankfully the authorities spotted the device and disarmed it before it went off. This sort of info though is worth noting as it can impact you and where you get property. These folks might not be the best neighbors, and might eventually have some sort of stand off or conflict with the government.
A lot of what you deal with in TX is similar in Eastern WA. Lots of ranchers, and cowboys. Water is highly important. Grazing of course comes up, needing to fence your property to keep the cows out. etc...
One of the major Orchard companies in the Okanogan recently shut down from what I hear from my neighbors. As well as I heard today that most of the gravel companies have shut down. So sounds like there is a bit of a job crunch happening for a lot of folks in the county.