The Rangitikei River has a catchment area of 1,230 square miles and rises in the Kaimanawa Ranges. Its catchment ranges in width from 18 to 27 miles. While the Rangitikei itself drains the whole of the eastern Kaimanawa and most of the western Ruahine Ranges, its major tributary, the Moawhango River (306 square miles), drains the south-west of the Kaimanawa Ranges.
A smaller tributary, the Hautapu (117 square miles), rises at the southern edge of the Ruapehu ring plain at Waiouru. The total length of the main river is 115 miles. It is a steep-gradient river carrying very large quantities of shingle in its bed. It flows in a steep-walled gorge as far as Marton and has a striking series of climatically developed terraces above the gorge.
About half the catchment lies in an area of rain shadow, and floods are rather small and infrequent.
The meaning and origin of the name are obscure.
by Thomas Ludovic Grant-Taylor, M.SC., New Zealand Geological Survey, Lower Hutt.