Rangitikei River

This is what Wikipedia has to say about the Rangitikei River.

"The Rangitikei River is one of New Zealand's longest rivers, 185 kilometres (115 mi) long.

Its headwaters are to the southeast of Lake Taupo in the Kaimanawa Ranges. It flows from the Central Plateau south past Taihape, Mangaweka, Hunterville, Marton, and Bulls, to the South Taranaki Bight at Tangimoana, 40 kilometres (25 mi) southeast of Wanganui. The river gives its name to the surrounding Rangitikei District.

In 1897 the river flooded and all six bridges over it were damaged or destroyed. The port at the mouth of the river was also washed away and never rebuilt.

The river is a popular leisure and recreation area for jetboating, white water rafting, kayaking and fishing, and includes public camp grounds along its banks, including Vinegar Hill. Its sheer vertical "paapa" (clay) cliffs (unique to this part of New Zealand) and deep canyons provide the perfect setting for adventure activities such as bungy jumps and flying fox rides. Part of the river was used as the Anduin River in Peter Jackson's movie The Lord of the Rings: The Fellowship of the Ring."

This was taken from the Vinegar Hill rest area.