With GOOGLE maps and the website "Historic Aerials", you can piece together a lot. HA has access to old topo maps and those are excellent in identifying railroad ownership.

Amtrak does not use the Peoria and Western line leaving Indianapolis. That line used to run next to the race track in Speedway where the 500 race is held, and that segment of it has been abandoned. Leaving Indianapolis toward Chicago, Amtrak uses the ex-PRR line that used to go to St. Louis to a place shown on old maps as "Sterling Heights" where it turns north onto another ex-PRR line that goes to Lebanon and Frankfort. It takes this line as far as Clermont. Near Robey Elementary School it then uses another transfer track onto a portion of the ex-NYC Peoria and Western that has not been abandoned and it takes that line to Ames, on the outskirts of Crawfordsville, where it joins the ex-Monon.