Ellis and Burnand opened a sawmill in Manunui in 1901, specialising in milling kahikatea to make boxes of its odourless wood for the butter export industry.[3] After the North Island Main Trunk Railway reached the settlement in 1903, the mill grew to be the largest in the region. It closed in 1942.[2]
Manunui became a manufacturing and farming centre as the native forest around it was milled and cleared. At one point it was a town district (requiring a population of at least 500; the population was 515 in 1911[4]), but merged back with Taumarunui county in the late 1970s; today is functionally a suburb of Taumarunui.[5]