So there are several options for rotations and they apply to all students, not just the ones from WAMI. I'll give you my best current understanding. During second year you can apply to third year tracks or the Olympia LIC (I literally know nothing about the LIC, so I won't comment). If you do not apply to a track or the LIC, you will become a safari student, and your "home base" will be considered Seattle regardless of where you actually live.
Third year tracks are offered in the following locations:
Idaho (this means the state, not one city)
Wyoming (this means the state, not one city)
Alaska (this means the state, not one city)
Billings
Bozeman
Missoula
Greater Seattle (this means Greater Seattle, not Seattle)
Spokane
Wenachee
For third year tracks, 24 weeks (out of 42) will be guaranteed in that location. The remaining could be anywhere. All rotations will be assigned to you, but you can request certain locations (so if you live in Casper, you can request all Casper, but it's not guaranteed).
During third year you can apply to fourth year tracks. Just because you got a third year "track" doesn't mean you will get the fourth year track.
Fourth year tracks are offered in the following locations:
Idaho (this means the state, not one city)
Alaska (this means the state, not one city)
Montana (this means the state, not one city)
Spokane
For fourth year tracks, 12 weeks (out of 16+) will be guaranteed in that location. The remaining could be anywhere. This is different than third year because a good portion of your clerkships will be electives that you schedule yourself. I did not do an Idaho track, but I have spent a majority of my time in Idaho my forth year because I chose to schedule my electives there.
If you track in a location, that is your "home base" and housing and travel to that location are not reimbursed. So if you are part of the Billings track, you have to pay for your housing in Billings, but if you are sent to Anchorage for 6 weeks, your travel and housing are provided or reimbursed. If you are a safari student, your travel and housing is covered for everywhere but Seattle.
You will have to spend a specified amount of time both in Seattle and outside of Seattle. The specific amount of time is up for debate and it sounds like this would be best discussed during your interview. My requirement was 8 weeks in Seattle. I don't know how much time was required outside of Seattle, as I spent most of my time outside of Seattle so this wasn't important for me to remember.
Okay, I think that's the basics. Please ask more questions if this is confusing, because it probably is.