The river itself holds good numbers of rainbow and some brown trout.

the forest cover in the river valley is predominantly Tawa and podocarps from the river level to about 700–800 metres, before transitioning to predominantly Tawai (beech) forest.

The mountain range on the west side of the Horomanga is steep and rugged, with thick almost impenetrable bush.

The east side of the Horomanga is a sharp contrast to the west, as the bush here is more open, and the hills less steep.

However, care should be taken when hunting on this side of the river, for the lower, less defined ridgelines of this area are easy to get disorientated or lost in.