The river flows generally southwest from its sources in the Kaimanawa Range 35 kilometres (22 mi) east of Mount Ruapehu to reach Lake Moawhango.

Lake Moawhango was formed by a dam in the New Zealand Defence Force's Waiouru Military Camp training area at the southern end of the Rangipo Desert, 10 kilometres (6 mi) north of Waiouru.

This lower section of the river flows through steep sided gorges making it difficult to access.

In 2008 complaints were made about impact of the diversion of water from the river, particularly silt build-up.

[1] The river is noted for its predominantly brown and rainbow trout.