I can't speak for tdma much, since its been a long time since i had tdma
sorry, but there is a good chance your phone will be roaming. I don't think
there is tdma coverage, but last time i was there i had occasional gsm
coverage with t-mobile and attws. Last time i was there my attws gsm phone
roamed on tmobile if it diddn't get an attws signal (which was very little
native attws coverage) and my tmobile phone works flawlessly from chicago to
peoria via the galesburg route.

Attws gsm signal has expaned a lot in the galesburg/peoria area. No tdma
service though. sorry.