Timing

Careful in winter. Best only attempt Rocky Mountain when it hasn't been frosty. Otherwise just do the lake circuit or up to Diamond Lake Lookout.

Access

From Wanaka, follow Wanaka Mount Aspiring Road 18.5 km to the signposted parking bay.

Track

There’s a network of tracks here including Diamond Lake Circuit (2.5km 45 minutes return), Diamond Lake Lookout (2 km 1 hour return) and Lake Wanaka Lookout (5km 2 hours return). This track incorporates all the others and includes the best lookout of all at Rocky Mountain.
There is a map of the track network at the stile entering the reserve.

Skirt the edge of Diamond Lake and start the climb over the copious structures to the platform above Diamond Lake. You can see why the lake was named as such. Continue climbing past rock bluffs, scramble over some slippery sections in groves of scrub and then exit onto the grassy tops between schist outcrops.

Rocky Mountain Summit is reward and one of the finest view points around, especially considering its relatively low altitude. The descent continues past the short detour to Lake Wanaka Lookout and arrives back at Diamond Lake. Continue around the lake back to the parking area (with toilets).

Geology

The entire area around Mount Aspiring National Park and Lake Wanaka underwent glaciation over several periods during the last 2 million years. Each successive penetration by the glacial advances obliterated what had gone before.

During the last Pleistocene, with it’s maximum around 17,000 year ago, glaciers descended the Matukituki Valley and met with others at Lake Wanaka, excavating deep valleys. Advances carved the inclined beds of the schist rock.

One notable feature is known as a roche moutonee - or rock sheep. An outcrop of resistant rock has the effect of slowing a glacier in its tracks, arresting its flow and diminishing its erosive powers. An attenuated slope results. Conversely on the downstream side, an acceleration increases its erosive power, giving a steeper slope. Observed from a side view, the shape resembles a sheep - at least it did to French geologists who first described these features.

Rocky Mountain is one of these roche moutonees. Mount Iron in Wanaka is another.