The 1238 hectares of land, largely covered with dense native forest, are owned by the New Zealand government and is managed by its Department of Conservation.
[1] Before Crown ownership, the land was owned by Manuel and Evelyn Tuanui.
This small burrow-nesting seabird had been considered extinct for over 100 years, and remains critically endangered.
[5] The reserve comprises an area of forested, peat-covered tableland dissected by the Tuku River and its tributaries and dominated by tarahinau.
The valley also contains kōpi, karamū, hoho and matipō, with abundant tree ferns.