Paso Abra del Acay — Cachi to San Antonio de los Cobres via South America’s Highest National Road (Northbound High Desert Run)
South America's highest national road. No guardrails, no mercy.
Ruta Nacional 40 touches its absolute ceiling at the Abra del Acay, a 4,895-metre (16,060 ft) pass in the Salta puna that holds the title of highest national road in South America. The northbound run from Cachi climbs out of the green Calchaquí Valley through a series of steep, rocky switchbacks where the gravel gives way to loose stone and the air thins enough to remind your engine — and your lungs — that this isn’t a casual drive. Above 4,000 metres the landscape strips to pure volcanic plateau: wind-scoured rock, salt-encrusted quebradas, and vicuña picking their way across the road with complete indifference. The descent toward San Antonio de los Cobres drops into the Puna de Atacama edge country, where the train to the clouds crosses the road and salt flats begin to shimmer on the horizon.
This is an expert-level day run requiring a strong, properly acclimatised 4WD with a snorkel or at minimum a well-tuned carbureted engine — fuel injection cars can struggle significantly at this altitude. Carry full jerry cans: fuel in Cachi is the last reliable stop. No fuel is guaranteed in San Antonio until you confirm beforehand. Snow and ice can close the pass any month of the year; spring and autumn bring the steadiest windows. No permit required. No cell service above Cachi. A sat communicator is strongly advised. This road is raw, beautiful, and utterly unforgiving of mechanical failures.
Trail Specs
| Difficulty | Expert |
|---|---|
| Trail Type | High Clearance, Overland Route, Technical 4x4 |
| Surface | Gravel, Mixed, Rock |
| Features | High Altitude, Historic, Remote, Scenic |
| Length (miles) | 99 mi / 160 km |
| Duration | 1-2 days |
| Max elevation (ft) | 16060 ft |
| Best season | April-June, September-November |
| Minimum vehicle | Capable 4WD, high clearance, acclimatised |
| Nearest town | Cachi, Salta |
| Land manager | Dirección Nacional de Vialidad (Argentina) |
| Permit required | No |
| Cell service | None |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Official sources | Dirección Nacional de Vialidad Salta Provincial Tourism |
| Verified | |
| Start coordinates | |
| End coordinates | |
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Location
Trail Conditions
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Frequently asked questions
Can a stock Land Cruiser or Defender handle this, or does it need to be built up?
A stock Land Cruiser 200 or Defender 110 with high clearance can physically complete the route, but at 16,060 ft your engine loses roughly 40% of its power — turbodiesels cope better than NA petrol rigs. Lift, lockers, and skid plates aren't required, but they're not a bad idea on the rocky descent north of the pass.
Is Paso Abra del Acay passable in winter?
July and August are the driest months but also when the pass sees frost, ice, and occasional snow closures — the road can shut without warning. Stick to April–June or September–November for the best odds of a clear crossing; always check current conditions with locals in Cachi before you roll out.
Do you need a permit or pay any fees to drive Ruta Nacional 40 over Abra del Acay?
No permit or fee is required — this is a national road managed by Dirección Nacional de Vialidad and it's free to drive. Foreign-registered vehicles entering Argentina need standard Aduana documentation, so have your título and any temporary import paperwork sorted before you leave the border.
What's the hardest section and what exactly makes it technical?
The climb from the south out of the Calchaquí Valley to the summit is the crux — steep loose gravel, off-camber switchbacks, and zero guardrails above serious exposure. The descent north toward San Antonio de los Cobres adds washboarded rock sections and shallow rio crossings; combine that with altitude-hammered power output and one wrong line puts you over the edge.
How far is the nearest gas station, and is there any water on route?
Fuel up fully in Cachi before departure — there's no reliable gas until you reach San Antonio de los Cobres roughly 100 miles north, and even there supply can be inconsistent, so carry a jerry can. Water crossings exist on the northern descent, but treat all surface water; there are no potable water points on the route itself, so carry at minimum 10 liters per person.
Trail track
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