Omahu, the Maori name meaning “running silently”, “escaping” and “a place of healing” was given to the area following an escape through the bush by several of the followers of a Maori chief who had been killed in a skirmish on Coopers Knob.

The land was part of Sir Heaton Rhodes’s Otahuna estate. Following his death in 1956, the Crown acquired 1978 hectares, and in July 1957, the land was divided into small farm lots sold to returned servicemen under the Rehab Loan scheme.

The Prendergasts acquired about 450 hectares including a house which may have been Sir Heaton Rhodes head gardener’s residence. They cleared the lower part of the land, but left the upper slopes in bush. In the early 1980s, Dr. Brian Molloy, an academic at Lincoln College and an honorary botanist for the Summit Road Society, suggested protecting the bush on the upper slopes by means of a Queen Elizabeth II Open Space Covenant in return for the Queen Elizabeth II Trust paying for the fencing. The Prendergasts agreed and the Covenant was signed in October 1985.

The Queen Elizabeth II covenanted area was sold in 1998 to the Gama Foundation, a charitable trust established by Grant and Marilyn Nelson. The Foundation then embarked on a pest control programme and renewal of fencing, as the bush had suffered from the actions of feral goats, pigs, deer and possums.