[2][3] Before construction of the North Island Main Trunk Railway began in about 1904,[4] most of the valley was a dense podocarp forest.

When the river was high enough, kayaks went 23 km (14 mi) from the Whakapapa Intake to Ōwhango bridge.

However, Intake Road was closed when a Landcorp farm passed to Te Kotahitanga a Ngāti Tūwharetoa on 1 July 2019.

[7] However, the upper reaches were diverted from the Whakapapa Intake, via tunnels (about 11 km (6.8 mi) and 5.5 km (3.4 mi) long and over 3 m (9.8 ft) in diameter),[13] Te Whaiau Stream and Lake Otamangakau reservoir to Lake Rotoaira, as part of the Tongariro Power Scheme, built between 1964 and 1971.

[19] There was a major sector collapse without eruption of Ruapehu about 9500 years ago that impacted on the upper catchment.