I've lived in Idaho, Utah, and Colorado. Can't really go wrong with any of them. Idaho is easily the most "rural" of the bunch. 30 minutes from Denver, and you're pretty much still in Denver. 30 minutes from SLC, you're pretty much still in SLC. 30 minutes from Boise and you could in the mountains, in the desert, or in the middle of farmland. A few years back I traveled to various workplaces throughout the Boise (and surrounding) area, and there are some very rural settings within a short distance of Boise. Kuna is close (20 minutes from Boise)...although I don't know if feels all that rural anymore due to how fast the area has grown. Emmett, ID is about as rural as I would ever get, and it's probably 40 minutes or so from Boise. If you aren't in the Air Force, just stay away from Mountain Home.
If you really want to be 1-2 hours from a "bigger" city, you might take a look at Twin Falls, Idaho. 120 miles from Boise and about 220 miles from SLC.
I did spend some time in a small town near Four Corners. Cortez, CO. I kind of liked he feel, but it was awfully far from any major population center.