The Railroad Commission of Indiana was established in 1906, considerably later than the equivalent Railroad and Warehouse Commission of Illinois, which was established in 1871. The earliest interlockings were registered with the Railroad Commission of Indiana, but information is not as comprehensive as such information for Illinois. Information was only included in the 1908 Annual Report of the Railroad Commission of Indiana. And years registered were included only for the first three years of existence for that agency.

In this list, towers are listed in alphabetic order, generally according to city. Also identified are the railroads and the lines involved, which are explained through a separate link below.

Indiana Towers 1906

Railroads And Lines

Some interlockings were later eliminated through grade separations.