You need to look at the regional carriers... You mentioned Colorado, Wyoming, and Montana. Union Wireless is a regional GSM provider mostly in Wyoming but with towers in Norther Colorado and possible southern Montana. They have by far the best GSM coverage in Wyoming, but people travel out of those areas from time to time. Union needs a reasonable cost effective way to allow roaming . This will help ensure that.
Union needs a reasonable cost effective way to allow roaming . This will help ensure that.
If they have the "best GSM coverage in Wyoming" there's a simple way for them to get cost effective roaming. Don't allow AT&T customers to roam on their network at a reasonable rate unless AT&T allows Union customers to do the same on the AT&T network.