The Rangitata braids out of the Two Thumb and Arrowsmith ranges across the south Canterbury plains, splitting around long shingle islands below its rugged gorge. A renowned sea-run salmon river, its summer run draws anglers to the mouth and lower braids, while the gorge and clearer channels hold strong brown trout.

Wading: Braided glacial channels, cold pushy water, unstable shingle — serious care

DOC benthic monitoring found mayflies made up nearly a third of sampled invertebrates, dominated by Deleatidium, with caddis a further 6 percent — a strong food base confirmed directly, but no adult emergence window has been documented.