Some externships have short rotations in different areas of the state or even different parts of US/Mexico, but, for the most part, you will be at the main residency hospital or affiliated clinics in the same city. Gusty gave you a good link...
A couple of residencies I have seen divide up the residents somewhat
(see the new mexico va; I think that is the one where you spend some time in CA w/Kaisar)
However, in general you do all 3 years (besides some externships like Feli mentioned) at the program (which may include various hospitals/clinics in the area).