Those analog "heavy iron" puppies, when in an area that requires step-up to the maximum of 3 watts became more broadcast units than cellular units. That analog, step-up concept was developed in the late 1970s as part of Bell Labs development of AMPS (advanced mobile phone service). Those folks were replacing an "ancient" broadcast VHF wireless telephone system with the technology available at the time.
Had we not gone digital, the system would have been exhausted several years ago.
As to Cingular I don't believe they have an analog fallback option in their system. It might be down to Verizon now and I suspect they have plans to cut away from that, but are being held back by GM's old analog-based OnStar system.
The problem the cattle buyer has out in the boonies is the lack of demand for service. Small demand equals small investment in cell sites. What someone like that probably needs is to pony up the bucks to be on a commercial two-way system with lots of rural coverage, somewhat like the county mounties have in Big Sky country.