Lake Sylvester & Lake Lockett Loop: A 2-day tramp in Kahurangi National Park

The Lake Sylvester & Lake Lockett Loop is a fantastic two-day tramping adventure in Kahurangi National Park on the Lockett Range featuring seven alpine lakes, open ridgelines, beech forest and some enjoyable scrambling. If you like trip with diverse terrain and alpine lakes, then this is your trip. There’s absolutely no shortage of lakes here between Lake Sylvester, Little Sylvester, Iron Lake, Lake Lillie, Ruby Lake, Diamond Lake & Lake Lockett.

This trip report shares the trip I did with my local tramping club, Wellington Tramping & Mountaineering Club. This report covers the route-finding information, camping information and what to expect along the way.

Topographic map showing the 2-day Lake Sylvester & Lake Lockett Loop tramping route in Kahurangi National Park, showing Lake Sylvester, Little Sylvester Lake, Iron Hill, Iron Lake, Ruby Lake, Diamond Lake, and Lake Lockett. — Map showing the Lake Sylvester & Lake Lockett route with our camp spot marked in blue

Fast Facts Planning Information

Location: Kahurangi National Park
Topo50 Map: BP 24 Takaka
Duration: 2 days, 31.6km, 2,318m elevation gained
Difficulty: Moderate due to off track navigation required beyond Lake Sylvester. However, there is a well-worn foot trail and plenty of rock cairns and the ridgeline from Iron Hill is easy to navigate especially since Diamond Lake is visible when descending towards it. The Diamond Lake Stream Trapline trail is also well marked. Stream crossings are all unbridged along the trapline.
The detour up Mt Lockett is advanced as it requires off track navigation and a far more technical scramble
Start / Finish: Cobb Dam Road (off SH 60 at Upper Tākaka)
Road Access: The road is unsealed from the Cobb Power House. The road is narrow, has steep drop offs and can be difficult to pass another vehicle – care is required and 4WD is recommended in winter due to ice and or snow. The road is 28km.
Direction: Can be walked in either direction but would recommend heading towards Lake Sylvester first to get the climbing and open ridgeline done while fresh
Huts: Sylvester Hut (serviced, bookable, 12 bunk hut), Trilobite Hut (standard, 12 bunks)
Camping: Plenty of camping spots around all the lake with multiple camping spots under the beech trees next to the outlet of Lake Lockett with a long drop toilet nearby. Plenty of camping next to the top end of the Cobb Reservoir with long drop toilets and no camping fees required
Best Season: November – April due to warmer weather for swimming and longer daylight hours
Dogs: No. National Park rules apply
Other Trips in Kahurangi National Park: Matiri Range & 1000 Acre Plateau via the the Haystack & Needle; Mt Owen via Bulmer Lake

Our Route Overview

Section	Time (hours)	Elevation Gained (m)	Distance (km)
Sylvester Lakes Track carpark → Lake Lockett	7	1,342	17
Lake Lockett → Sylvester Lakes Track carpark with trip up Mt Lockett	6	976	14.6

Sylvester Hut and Lake Sylvester

The DOC track starts from the northern end of Cobb Valley at the Cobb Dam and it is an easy, non-technical 500-metre climb on the Sylvester Lakes Track through beech forest to Sylvester Hut. Anne and Lynsey were both wearing unicorn headbands—you never quite know what to expect on a club tramping trip!

Hiker wearing a white unicorn headband with a purple horn carrying a backpack while walking along a gravel trail in Kahurangi National Park towards Sylvester Hut. — Unicorns out tramping

Passing Sylvester Hut, we continued towards Lake Sylvester and its smaller sibling, Little Sylvester Lake. These were the first two of the seven lakes we would pass over the two-day Lake Sylvester & Lake Lockett Loop/Lockett Lakes Loop.

Iron Lake & Iron Hill

The official DOC track ends at Lake Sylvester, but a well-worn foot trail marked by rock cairns continues all the way up to the summit of Iron Hill. We stopped for lunch near the outlet of Iron Lake before continuing the climb towards Iron Hill. The view from the summit back down towards Lake Sylvester, Little Sylvester Lake, Iron Lake and the Cobb Valley was spectacular. This section would be well worth doing as a day trip in its own right.

Toy dinosaur sitting on a rocky summit of Iron Hill with Lake Sylvester and Little Lake Sylvester visible in the background in Kahurangi National Park — A dinosaur spotted out in the wild on Iron Hill enjoying the view back down towards Lake Sylvester & Little Sylvester Lake

Tramper standing on a rocky outcrop on Iron Hill enjoying wide views of mountain ranges and view down into the Cobb Valley — The view from Iron Hill back down to the Cobb Valley

Tramper with a backpack standing on a rocky outcrop enjoying wide views of mountain ranges and valleys along the Lockett Lakes Loop including Lake Lockett — Lynsey enjoying the views from Iron Hill with Lake Lockett in the background

Iron Hill to Diamond Lake

The ridgeline towards Point 1631 above Lake Lillie was a fun scramble. Nothing technical, but the narrower ridge required a little more concentration and made for an enjoyable section of the route.

High-angle mountain view looking down into the basin containing Lake Lillie along the Lake Sylvester & Lake Lockett Loop route. — One can never have too many lakes – Lake Lillie

Trampers scrambling along the rocky alpine ridgeline near Point 1631 above Lake Lillie on the Lockett Lakes Loop in Kahurangi National Park. — The fun ridgeline towards from Iron Hill to point 1631

Group of tramping club members negotiating a steep, narrow rocky section of the ridge after Iron Hill on the way to Diamond Lake — ‘Be the goat’ on the ridgeline above Lake Lillie

A few of us continued further along the ridge to get a better view of Ruby Lake, before descending towards Diamond Lake.

High-altitude view of Ruby Lake nestled in a valley surrounded by bush and tussock along the Lockett Lakes Loop route in Kahurangi National Park. — Looking across to Ruby Lake

This section was more awkward, with uneven terrain, thick tussock, spaniards and high vegetation making it difficult to see our feet – and sometimes even each other. The more usual route is to descend from Iron Hill towards Lake Lillie, before dropping down to Diamond Lake from there but we had followed the ridgeline further along to get a view of Ruby Lake.

⚠️ Route note: Descend down to the Lake Lillie outlet from the saddle between Iron Hill and point 1631. From Lake Lillie, sidle around above the bush until you are above Diamond Lake, then descend through the bush to the lake. Don’t drop down too soon, as you can end up below the lake. If you’re unsure, follow the edge of the bush around to the top of Diamond Lake and then follow the shoreline.

View from high alpine tussock slopes looking down toward Diamond Lake nestled amongst the bush with Lake Lockett and Mt Lockett in the background — Looking down at Diamond Lake with Lake Lockett in the background

Scenic shoreline view of calm blue waters at Diamond Lake framed by golden tussock and beech-covered hills. — Diamond Lake

Diamond Lake to Lake Lockett

Once we reached Diamond Lake, we found a rough but faint trail circumnavigating the northern end of the lake. We met another group preparing to camp there for the night, while we continued along the well-marked trapline trail towards Lake Lockett.

⚠️ Route note: The first marker is on the true left 10-20m below Diamond Lake outlet. From here the trail is well marked and generally easy to follow.

We eventually reached Lake Lockett, where we found multiple fabulous campsites beneath the beech trees. The campsite is clearly a popular local one. It even has an open-air long drop toilet to help keep the area tidy.

Dinner was the usual club communal one. Anne had even organised a treat— deconstructed apple crumble, complete with unicorn and rainbow cake decorations. Tramping doesn’t get much better than that!

Deconstructed apple crumble in a camping pot topped with chocolate, unicorn sprinkles, and a toy dinosaur at Lake Lockett — The dinosaur certainly approved of the deconstructed apple crumble for pudding

Lake Lockett and Mount Lockett (1,621m)

The following morning, the boys and I headed up from camp onto the ridge above Lake Lockett. This was a more technical scramble than the previous day’s ridge, and we all really enjoyed it.

At the summit of Mount Lockett, we split into two groups. One group headed back down the same way to camp, while three of us continued along the ridge.

Wide alpine vista from the summit of Mount Lockett looking down over Lake Lockett and surrounding mountain ridges. — View from Mt Lockett

It was cold and windy on the ridge above Lake Lockett, which gave us plenty of motivation to keep moving. As we descended towards the bush, we picked up a faint ground trail that led us towards the outlet of Lake Lockett.

Looking down from Mount Lockett at the dark waters of Lake Lockett and nearby alpine tarns surrounded by native beech forest. — If you haven’t seen enough lakes, there’s still more tarns above Lake Lockett. View from Mt Lockett

Walking out on the Diamond Lake Stream Trapline

From Lake Lockett it was an easy walk down the valley on the trapline next to Diamond Lake Stream. Instead of the usual DOC orange markers, this section was well marked with red tin lids. This trail isn’t an official DOC trail but rather a trapline maintained by volunteers who are happy for people to use it at their own risk.

⚠️ Route warning: The Diamond Lake Stream Trapline crosses multiple stream crossings that could be impassable after heavy rain.

At Battery Creek the track begun an upward sidle to the quarry. Once at the quarry it was an easy 1.5km walk down the 4WD road to the carpark.

We were fortunate enough to get phone reception here so we could call the other club group. They came to pick us up so we could all spend the night at Trilobite Hut.

Hiker wearing a pink hoodie standing next to large spaniard /speargrass plants with tall brown seed heads along the Lockett Lakes Loop route — Speargrass on steroids. Anne demonstrating how tall the spaniards/speargrass plants really were

The Lake Sylvester & Lake Lockett loop was an easy and fun weekend trip with spectacular scenery including all 7 lakes and would be a trip I would highly recommend.