No airport, although it is at the nexus of several small roads that connect WA and ID independently of the main roads. So it could be a useful duck-down-the-alley kind of bypass. The terrain is low hills with higher ground to the east.

Edit: Looking at more maps of the PNW. Farmington is a very convenient dodge point that isn't on most, but in general there is a corridor from the Columbia to Canada and about 60 miles wide which is very sparsely traveled and could be a smuggling route.

Edit again: Continuing south of the Columbia one goes through the Oregon outback, another road less traveled, and eventually Nevada and the Loneliest Road in America. Could be smooth sailing for an invading army from BC, or a good reason for these three states to hang together for various nefarious purposes. And after Nevada, Arizona.