Mt Robertson summit via Pukaka Valley offers a solid day tramp, mostly in native bush, close to Blenheim and Picton. By Chris Cookson

Signs at the car park suggest 5hr to the summit, however it can be reached in about 3.5hr if you’re moderately fit. Check the forecast before setting out as the summit is often shrouded in cloud.

Head north for the first couple of kilometres along the well-maintained Pukaka Valley Track, which follows Pukaka Stream through mixed native forest of podocarps, tree ferns and beech. A DOC sign identifies the start of the climb to the ridge. There is no water beyond this point.

The track narrows here and is unformed in parts as it climbs steeply for about 300m through beech forest. The gradient eases for the last 100m of ascent and reaches a junction with the Mt Robertson Loop Track on the ridge line.

Turn left along the broad ridge track with its moderate gradient. Be alert, as mountain bikers share this track and the clay surface can be slippery when wet. There are muddy patches too, so robust footwear is a must. There are frequent signs of pigs and goats along the ridge. 

At a small clearing about 500m past the track junction, enjoy views of the Wairau Valley and Richmond Range. 

The beech forest gives way to shrubby vegetation, such as mingimingi, lancewoods and
kānuka. After another 500m, at a second junction, the loop track leads down to Whites Bay. Keep left and continue onto the Mt Robertson Summit Route.

Several hundred metres after this junction, about 3km before the summit, a memorial plaque on a rockface to the left marks where a Sounds Air Cessna Caravan crashed into the ridge in January 1996, killing all five passengers.

After a steady 2km zigzagging climb on a wide, well-defined path to over 700m, the track descends before a steep ascent through the bush. A rocky scree area at about 950m offers respite and the best views of the whole tramp, south to Cape Campbell and the Inland Kaikōura Range including Tapuae-o-Uenuku and, on a good day, northeast to the south coast of the North Island. There is mobile reception at this point. 

From the lookout the summit is about 1km away. The track descends briefly before a final short, sharp climb through bush, then levels off for the last few minutes through moss and
lichen-festooned forest.

At the 1036m summit is a large clearing with a radar station and trig. There are no views to be had, but the surrounding forest makes a sheltered spot for lunch.