At Mukinbudin, the line now terminates while, in the past, it extended all the way to Southern Cross, where it connected to the Eastern Goldfields Railway.

[5] The Southern Cross-Bullfinch Railway Act 1910, an act by the Parliament of Western Australia assented to on 21 December 1909, authorised the construction of the eastern end of the railway line from Southern Cross to Bullfinch,[6] with the contract awarded to the Western Australian Public Works Department on 10 December 1910.

[10] The contract for the section from Bencubbin to Lake Brown was awarded to the Public Works Department on 11 November 1920 and it was officially opened on 15 October 1923.

[12][13] In 1954, the state government of Western Australia had compiled a list of loss-making railway operations, of which the Wyalkatchem to Bullfinch section of line was one.

The Wyalcatchem to Mukinbudin had a total expenditure of almost four times its earnings in the financial year to June 1953, while the other two sections were considerably worse.

The Lake Brown to Bullfinch section of the Southern Cross railway line had an expenditure of £A 17,515 versus earnings of £A 425.