- Ruataniwha Conservation Area
- Track starts at car park at Gretas Stream on Glen Lyon Rd, 20min from Twizel
The route to the summit begins at a car park on the southern bank of Gretas Stream. A few minutes from the lake is a derelict hut, dating from the 1890s. Today the hut is like something from a museum, while 100 years ago it would have been a welcome outpost offering respite in an unpopulated and sometimes harsh land.
From the old hut, the route turns south-east and follows a 4WD track that zigzags to near the top of Ben Ohau. Although not used by vehicles anymore, the track makes an excellent wide benched path.
After 45min, the track crests the ridge and offers excellent views of the lake and surrounding mountains. One particularly obvious feature is the access road to the Lake Ohau ski field high in the Ohau Range across the lake.
From here, the track cuts one long unbroken line to the north ridge, crossing this just below the summit. Leave it here to walk the 10min to the apex, where you're rewarded with breathtaking vistas of the Mackenzie Country.
Rejoin the 4WD track, which descends sharply down a basin and follows a feeder stream of the Gretas through remnant stands of beech, manuka and totara.
After nearly 4km there's a short climb to leave the feeder stream and gain a shoulder at about 700m on the true right of the stream. And from there it's all downhill back to the lake's edge.