Lived here five years -- have NEVER had any reception or signal problems anywhere in Great Falls. Once you get outside city limits, however, coverage can be pretty spotty (such as in Belt, Monarch, etc).

Formerly Western Wireless Corporation / CELLULARONE has already upgraded all of their TDMA towers into GSM in Montana, however it was only work inside major cities, and now it works mostly outside of major cities like Williston, ND, Glassow, Wolfpoint, Glassow, Malta, Dodson, Harlem, (Not Chinook), Havre, and other route (Highway 86) from Havre, Big Sandy, Loma, Fort Benton, and here in Great Falls. I also saw more coverage also from Mile City along I-90 all way through to Missoula. I have no idea if Belgrade, Bozeman, or other surrounding area by I-90.. cuz Im closer to Hwy. 2 that I know where that works. I hope anyone can tell us about their experience in closer I90 and I-15 areas. So we can know that would work there also. However my Sidekick did work like a charm in the area that I go through mostly since Im able to use Yahoo!, AIM, or Browser and etc just fine.

T-Mobile really isn't present in MT but if you go to Missoula, Kalispell, Great Falls, and other cities you will get reception though it will be spotty at best. No reception whatsoever outside a city though.

No reception following I-90 from Souix Falls, SD to Great Falls, MT. I was in Montana for 3 weeks and found no reception anywhere.

Just received a letter from AT&T that they will be canceling my cell service due to lack of usage on their network. They say I must use 50% of all calls and data service on their network. Since I travel all over the nation but live here in Great Falls that was not supposed to be an issue but since I took 6 weeks off and stayed at home they are "willing" to either cancel my service with no cancellation fee or set my phones up to not work unless they are on the AT&T network.