Boundary Stream Mainland Island is situated on the eastern flanks of the Maungaharuru Range, about 60 km northwest of Napier.
It extends from lowland forest at 300 m above sea level to montane forest. It is home to a number of threatened species including North Island brown kiwi, kākā and kōkako, New Zealand falcon and kererū.
The teaching resource explains the concept of conservation management in what is termed 'mainland islands' and provides further information on the biodiversity, history, geology and landform and recreation opportunities available at Boundary Stream Mainland Island.