This Reserve includes the wet summit lands of the Kohala Mountains, with two rare kinds of montane bogs surrounded by ‘ohi‘a forests, shrublands, and grasslands.

The Reserve extends downslope to the Kohala sea cliffs and a coastal dry grassland. Rare plants are known from bogs and forests. The steep cliffs of Waipi‘o and Waimanu valleys form part of the Reserve boundary. Numerous streams run through the area. The Reserve is an important watershed for the region.