The Rock Springs, WY and surrounding areas have very limited coverage as far as cell phones go. From what I found Verizon is going to be your best bet for getting coverage. The unlimited talk and text plans with lower priced carriers would not be beneficial since you will be unable to get service in this area. For a single line you can get unlimited talk and text with Verizon for $89.99 per month. I have had Verizon for several years and can say that they are worth every penny.