The former Big Four mainline west of Indianapolis. Both of those upper aspects sure look yellow, but based on position one of them ought to be green. Interesting…
The Big Four (ofificially the Cleveland, Chicago, Cincinnati & St. Louis) was acquired by the New York Central in 1906 but operated separately until 1930. Even after that, it was better known as the Big Four in its many on-line communities, though by the time of the Penn Central merger in 1968 its separate identity had pretty much faded away.
