Construction of this relatively short line took approximately two decades, and when it was completed, it linked the now closed Donnellys Crossing Section with the national rail network.

Construction from Waiotira on the North Auckland Line commenced in 1922, but Dargaville was not reached for another eighteen years.

In January 1931, the line was open to Tangowahine,[4] sixteen kilometres from Dargaville, but construction ceased for five years due to the Great Depression.

In 1940, trains commenced running to Dargaville, but the old railway station (used by the Donnellys Crossing Section) was closed and a new station built at a different location, delaying the formal opening of the Dargaville Branch until 15 March 1943, over twenty years after construction began.

[3] Typical motive power on the Dargaville Branch from its opening until the mid-1960s were steam locomotives of the AB and J classes.