Jefferson Railroad Line in "Monk" (Location)

At separate points in the story, both Monk (who had never ridden on a train before) and Gavin Stevens have significant emotional moments while traveling between Jefferson and the penitentiary. The story isn't specific about the route either of them take, but we assume they leave Jefferson on the tracks that run north and, like train riders in other fictions, change somewhere for a train that will take them to Parchman.