In November 1881, a line arrived from Terowie and the south, in 1882 it was extended north to Quorn.

[2][3] Thus Petersburg became a four-way junction station (all narrow gauge) and the town was the headquarters for the South Australian Railways narrow gauge network, with an extensive locomotive depot.

[3] Following the conversion of the Adelaide to Crystal Brook line to standard gauge in 1982, Peterborough's importance diminished.

[3] Today the former roundhouse is home to the Steamtown Heritage Rail Centre.

Journey Beyond's weekly Indian Pacific service passes Peterborough on its route but does not stop at the station.