As far east as Porter, the former Pere Marquette Railroad had trackage rights (since 1903), and was used by former Michigan Central trains beginning in 1957. All Amtrak trains serving points in Michigan presently use this route.
Radio Frequency - 160.800 (AAR Channel 46) (Whiting-Porter)
Radio Frequency - 160.620 (AAR Channel 34) (Porter-Elkhart)
506.0 Whiting
505.9 CP 505
503.4 CP 503 (junction-IHB/drawbridge)
502.9 Indiana Harbor
502.8 CP 502 (IHB crossing/remote-Hick)
501.0 CP 501 (junction-NS/CSX)
498.1 Pine
497.1 CP 497
496.0 Gary
491.0 CP 491
487.1 CP 487
485.7 Burns Harbor
484.9 CP 485
483.5 CP 483
482.2 CP 482 (junction-NS/Amtrak/CSX)
482.2 Porter
481.1 Chesterton
476.8 Burdick
473.4 Otis
467.5 Pinola
466.6 CP 466
463.8 CP 463
463.4 La Porte
462.4 CP 462 (NS crossing)
456.4 Rolling Prairie
450.1 New Carlisle
448.6 CP 448
448.4 Terre Coupee
443.7 Lydick
438.5 South Bend
437.5 CP 437 (junction-CN)
435.4 CP 435
432.7 Mishawaka
426.4 CP 426
423.1 CP 423
421.6 Elkhart
421.5 CP 421
2 tracks, CTC in use. Some segments of 3 and 4 tracks. CTC controlled from Dearborn, MI. Chicago Terminal Dispatcher controls trackage Whiting through CP 482, Elkhart Dispatcher controls trackage east of CP 482 to Elkhart.
Track diagram as the line existed until the 1950's, when much of the line still had four tracks.