Otira River

Otira River
Upper course with Otira Viaduct
Data
location	South Island , New Zealand
River system	Taramakau River
Drain over	Taramakau River  → Tasman Sea
source	at Mount Rolleston in Arthur's Pass National Park 42 ° 54 ′ 8 ″  S , 171 ° 31 ′ 23 ″  E
muzzle	below Otira in the Taramakau River Coordinates: 42 ° 45 ′ 0 ″  S , 171 ° 38 ′ 0 ″  E 42 ° 45 ′ 0 ″  S , 171 ° 38 ′ 0 ″  E
length	20 km

The Otira River is a river on the South Island of New Zealand . Its source is on Mount Rolleston in the Southern Alps . The river flows 20 km in a northerly direction, passes Otira and then flows into the Taramakau River as the only major tributary . The valley of the Otira River and the SH 73 form the north-western access to Arthur's Pass , one of the three important passes over the Southern Alps.