John O'Brien was born at Pannoobamawm (about 40 miles north of Bendigo) in 1874, on a farm selected by his father, Michael, in 1873. He went to school at Tennyson, and as his father was then blind, the boys took it in turn to go to school. At the age of 14, he became a contractor employing men, constructing outlet channels from the Waranga Basin; he did some contracting in the Minyip area, and later in the southern Mallee. About this time - about 1890 - the dog fence was opened and settlement of the northern Mallee was opened up.