It rises in the Domett Range in the Kahurangi National Park and flows north-west into the Heaphy River, which flows into the Tasman Sea.

[1] A swingbridge crosses the river near its junction with the Heaphy.

[2] Heavy rain in the Buller District in February 2022 caused significant damage.

The suspension bridge over the Gunner River was damaged but was deemed repairable, while the Pitt Creek bridge was swept away, and the suspension bridge over the Heaphy River was destroyed.

This article about a river in the West Coast Region of New Zealand is a stub.