Regulation No. 170 on preservation of Spålen-Katnosa nature reserve, Ringerike, Jevnaker and Lunner municipality, Buskerud and Oppland.

The Regulation ensures the preservation of a relatively undisturbed natural area of biological diversity in terms of habitats, ecosystems, species and natural ecological processes. The area is of particular importance for biodiversity and distinctive due to its few remaining large forest areas centrally in Eastern Norway - without major technical intervention. The area is of special scientific interest due to its great diversity of vegetation types and several rare and endangered species of fungi, lichens and mosses.