The Oronui Gorge is a 6km stretch of winding, deep river valley below Oronui Hut. On the map it looks tight and challenging, but on the ground it's not too bad. The river is quite small here, and the bed mainly of gravel and though it's wet feed all the way, crossings are easy in normal flows. Heavy rain, however, would close the route completely and sidling is not an option on the steep, bluffed valleysides.

The Oronui/Tapuaeroa River is the main access to Oronui Hut, and forms the most common eastern end-point for an east-west traverse of the Raukumara Range. Access is from the Tapuaeroa Roadend (Mt Hikurangi roadend) and is up the riverbed. The riverbed is good shingle until above the Huitatariki, where a gorge is encountered. This requires rock-climbing on the bluffy banks, and several dodgy crossings in pools between rapids - not places to get swept away. Once past this things improve.