The rules say start with Gallagher if it's first game, then lead proceeds to the left. A scoring sheet posted at Steve Jackson Games has spaces for multiple rounds. A single round takes about 30+/- minutes in my experience. So is a complete game a single round, or should you play as many rounds as live players and give everyone a chance to lead off?
Back in the days when there were less maps we played every map back to back
Ooh a little higher, now a bit to the left, a little more, a little more, just a bit more. Oooh yes, that's the spot!
From my recollection (caveat: having not played it since last year and not having a copy) when we played it two player we played four rounds, i.e. the lead was started by all four ranches. Two player took us an hour to play all four rounds.