The parks contain moist forest ecosystems, including large areas of rainforest and an area of endangered Lowland Rainforest. They also contain one endangered and three rare plant species, and fourteen threatened animal species.
The parks also contain a range of historic sites of local significance associated with the former Dorrigo branch railway, and a network of timber tramlines associated with local timber mills which are part of a group of timber tramways considered to be of state heritage significance.