The Calumet Region is the name given to the geographic areas drained by the Grand Calumet River and the Little Calumet River of northeastern Illinois and northwestern Indiana. In this region many Chicago-destined rail lines that come from the east make a turn along with the southern edge of Lake Michigan. Several north-south lines radiating from the city cross these lines, making for a good deal of rail intersections within a very compact area. Add in all the heavy industry along the lakeshore and one can see why to this day there’s such a proliferation of rail traffic in this geographical region. In volume one of our two part series we will examine several rail operations of the region, mainly within the state of Illinois. Locations included are Blue Island, Harvey Junction, Riverdale, the Dolton area, a brief glimpse of the Chicago Rail Link, and then we will work our way east towards many locations just inside the Illinois/Indiana border. A few scenes in the Hoosier state will be seen in our look at some South Shore operations and the final segments at Hohman Avenue and Hammond, Indiana.