The North Branch Ashburton River is a tributary of the Ashburton River system in Canterbury, New Zealand, flowing roughly southeast for approximately 98 km before joining the South Branch about 21 km from the coast. The catchment covers 490 km² at its mouth, with headwaters in the Palmer, Taylor, Black Hill, Old Man, and Mt Hutt ranges. The upper catchment geology consists primarily of intensely folded and faulted greywacke and argillite, giving the river a classic braided Canterbury character in its lower reaches and a more confined gorge character in its upper sections.

For packrafters, the primary run begins from the confluence at Cookies Point, where the river drops into a gorge described as a compact version of the Waimakariri. The following 10 km delivers consistent wave trains, with bluff corners and occasional mid-stream boulders. There are good eddies throughout, providing scouting opportunities, and the steady nature of the rapids makes it a suitable run for building river-running confidence. The trip is a through-run requiring either a 35 km bike shuttle or two vehicles. The walk-in starts from Redcliffe Stream at the end of Double Hill Run Road in the Rakaia Valley, following the marked DOC Redcliff Track. Cookies Point Hut and Tribulation Hut provide overnight options, making this a natural two-day trip.

Flow is a critical consideration. The river requires sufficient rainfall to be paddleable, and at around 12 cumecs on the gauge, the lower Swift Creek section from Cookies Hut becomes runnable. Below that level, portages become frequent. Tributary crossings on the walk-in can become challenging when the river is running around 14 cumecs or higher following significant rainfall.

Fishing regulations apply to the North Branch and its tributaries under the Central South Island Fish & Game Region. The season for trout and salmon runs from 1 October to 30 April and 1 October to 31 March respectively, with methods restricted to artificial fly and spinner on the North Branch and its tributaries. Bag limits are two trout. Paddlers should be aware of anglers on the water, particularly during the fishing season.

The river also sees some jet boating activity, primarily on the lower sections, though flows are boatable for jet boats only 5–10% of the time due to characteristically low flows.