Rooftop of New Zealand — Lewis Pass to Springs Junction via the Lake Sumner Forest Park High Road
South Island rivers that vote with depth.
Lewis Pass sits at 864 metres on State Highway 7, and most people blow through it in a rental car without a second thought. Turn off the tarmac onto the Lake Sumner Forest Park tracks and the whole story changes. The Doubtful River Road and the Ada Valley 4WD tracks cut through old-growth beech, cross braided gravel channels that shift every winter flood, and climb open tussock terraces with unobstructed views of the Main Divide. The river crossings at Ada River and Lake Sumner’s inlet streams are the gate-keepers — after rain they can stop a prepared rig cold. Hurunui No. 3 Hut is a landmark waypoint and a solid overnight base.
This is New Zealand high country at its most honest: no crowds, no cell coverage, and rivers that don’t care what your recovery gear cost. You need a capable high-clearance 4WD with a snorkel if you’re running it in shoulder season — water crossing depths vary from knee-deep to door-handle deep depending on the week. Best months are December through March. No permit required for vehicle travel, though hut bookings go through DOC. Carry UHF radio and a PLB. Fuel in Hanmer Springs or Reefton before you leave — there’s nothing in between.
Trail Specs
| Difficulty | Difficult |
|---|---|
| Trail Type | Backcountry, Technical 4x4 |
| Surface | Dirt, Gravel, Mixed |
| Features | Camping, High Altitude, Remote, Scenic, Water Crossings |
| Length (miles) | 68 mi / 109 km |
| Duration | 2-3 days |
| Max elevation (ft) | 4200 ft |
| Best season | December-March |
| Minimum vehicle | High-clearance 4WD, snorkel recommended |
| Nearest town | Hanmer Springs, Canterbury |
| Land manager | Department of Conservation (DOC) — Canterbury Conservancy |
| Permit required | No |
| Cell service | None |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Official sources | DOC Lake Sumner Forest Park page DOC tracks and access info |
| Verified | |
| Start coordinates | |
| End coordinates | |
| Copy both for Google Maps directionsClick to copy the directions URL · or open it directly in a new tab | |
| Find on Google | Search on Google → |
Location
Trail Conditions
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Frequently asked questions
Will a stock Land Cruiser 200 or Defender 110 handle this without modifications?
Stock high-clearance 4WD is the bare minimum, but a snorkel is strongly recommended due to river crossings that can run thigh-deep or higher after rain. A locker or at least a rear LSD helps on the loose, steep sections. Lift and all-terrain tyres aren't required but you'll be glad to have them.
When does the trail become impassable and what closes it?
December through March is the reliable window — snow can close the high sections any other month without warning. River levels are the bigger wildcard; a single rain event upstream can make crossings undriveable for 24–48 hours even in summer. Check NZ MetService forecasts and river level data before you leave Hanmer Springs.
Do I need a permit to drive through Lake Sumner Forest Park?
No vehicle permit is required for the route itself. Camping at DOC huts and designated sites may require hut tickets or campsite fees — purchase them through the DOC website or the DOC app before you head in, because there's zero cell service on the trail.
What's the hardest section and what actually makes it hard?
The river crossings on the Boyle and Hope River flats are where rigs get stopped — braided channels shift constantly and a line that worked last weekend may be axle-deep this weekend. The high-country saddle tracks are steep, loose, and narrow with exposure on one side and no room to turn around. Commit only when conditions are confirmed.
How far is the nearest fuel from the trailhead and is 109km of trail going to leave me dry?
Hanmer Springs has the last reliable fuel before you drop into the park — fill completely there. The 109km trail distance plus your drive in and out means plan for at least 200–250km of total consumption, much of it in low range, which kills fuel economy fast. Carry a jerry can if your range in technical terrain is under 400km.
Trail track
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