DESC: These days there are many Montanas. I live in Livingston, a railroad town 75 miles south of White Sulphur. It is still at the stage of having a charmingly split personality, with cowboy bars and art galleries and coffee houses mingling in happy profusion. Other Montana towns like Bozeman have been yupped into another time zone--say, Pacific Daylight--but this place, White Sulphur Springs, Meagher County pronounced Marr, is still firmly old Montana, Mountain time, 6:45 a.m. at the moment. Big country, open, mountains on the horizon, sagebrush and bunchgrass under snow, and not a Range Rover or a Humvee anywhere. That thought cheered me as I mashed the brakes to avoid a ribbon of whitetail deer streaming off an alfalfa field, over a fence and across the road. Ian Tyson, the magnificent Canadian cowboy singer, bounced along with me on the tape player: "Open up the gates boys, let my ponies roll/I'm gonna travel on the gravel, gonna head 'er for the setting sun." Hell, Ian's still cowboying, I thought, and