Traveling on CSX's Grand Rapids Sub, westbound Amtrak Grand Rapids to Chicago train, the Pere Marquette is 40 miles into the trip passing just east of Fennville, MI. Having made it's first station stop at Holland, ahead lie stops at Bangor and St Joseph/Benton Harbor, MI before arrival at Chicago Union Station in about 90 minutes.
Amtrak has three routes that connect Michigan with Chicago, but none to the East or South. The routes are: Wolverine - Pontiac - Chicago; Blue Water - Port Huron - Chicago, and Pere Marquette - Grand Rapids - Chicago.