 The river and most of its tributaries originate in the Fenian Ranges in the Kahurangi National Park, where the river flows through a section of the Honeycomb Hill Cave.Further downstream it continues through the Ōpārara Arch and the Moria Gate Arch, both of which are popular walking destinations.These sections of the Ōpārara River, while still in dense native forest, can be reached by a forestry road.