It is 71 km long and runs south to north down the Maruia river valley from SH 7 at Springs Junction, 15 km west of the main divide at the Lewis Pass, to SH 6 in the Buller Gorge, 11 km west of Murchison.

It forms part of the most direct route between Christchurch and Nelson.

It takes its name from a small settlement toward its northern end.

The road is sealed and two-lane, with some single-lane bridges.

Maruia Falls, a 5-m waterfall near the road, did not exist prior to the 1929 Murchison earthquake (magnitude 7.8).