How large of a region am I available for when I take the postal carrier test?

I live in NW Montana and I'm signed up to take the test in Moses Lake, WA (6 hours or so away). I'd rather stay where I live but am willing to move to get my foot in the door but I don't have much interest in moving to Moses Lake. I asked to Post Office and they said I was available in the "area" I took the test. Anyone know if that means within the city, county, state or region of the country? Also if I need to move somewhere I don't like how many years do you need to be employed before you can look into transferring? Thanks.|||8 1/2 by 11.