Paso de Agua Negra — Rodeo to Vicuña via the Andes High Desert Crossing
4,765 m of volcanic Andean desert and thin air.
Paso de Agua Negra climbs from the Argentine wine town of Rodeo through progressively more alien terrain — polychrome volcanic ridges, salt flats, and wind-sculpted rock formations — to a customs post at 4,765 m where the air is thin enough to feel and the temperature drops without warning regardless of season. The Argentine side follows Ruta Nacional 150 through the Iglesia Valley before the road turns serious: switchbacks with crumbling edges, no guardrails, and sections that require careful line selection when wet. On the Chilean side, the descent into the Elqui Valley is dramatic — the road carved into red-brown cliffs above the Río Turbio, dropping into one of South America’s premier pisco-producing valleys. The border crossing itself is only open in summer and closes with the first serious snowfall, typically April through October on the Argentine calendar.
This is an Expert-level crossing in terms of altitude and remoteness, not necessarily technical terrain — the road is dirt and gravel, not rock-crawling. The real hazards are altitude sickness, sudden weather changes, and the complete absence of help if something goes wrong in the high section. Run at least two vehicles. Carry fuel for 400 km from Rodeo; there’s nothing at the pass. The Argentine customs post at Las Flores and Chilean customs at Juntas are the only structures. Open roughly November through March — check PASO status before departing as closures happen fast. The volcanic geology and Andean wildlife (vicuña, condor) make this one of South America’s most rewarding desert crossings.
Trail Specs
| Difficulty | Expert |
|---|---|
| Trail Type | Backcountry, High Clearance, Overland Route |
| Surface | Dirt, Gravel, Mixed |
| Features | High Altitude, Historic, Remote, Scenic |
| Length (miles) | 155 mi / 250 km |
| Duration | 1-2 days |
| Max elevation (ft) | 15633 ft |
| Best season | November-March |
| Minimum vehicle | High clearance 4WD, dual spare, recovery gear |
| Nearest town | Rodeo, San Juan, Argentina |
| Land manager | Gendarmería Nacional Argentina / Carabineros de Chile |
| Permit required | No |
| Cell service | None |
| Water crossings | Yes |
| Dispersed camping | Yes |
| Official sources | Argentina border crossing official page Chile border crossing official page |
| 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
What's the minimum vehicle setup to drive Agua Negra?
High clearance 4WD is non-negotiable — this isn't a trail to test a stock SUV at 4,765 m. Bring two full-size spares, a compressor, recovery boards, and tow points; the loose volcanic gravel and steep switchbacks will punish anything underprepared.
When is the pass actually open, and what closes it?
November through March is the reliable window — snow closes the pass completely the rest of the year. Even in summer, unexpected storms can shut it down for days; check with Gendarmería in Rodeo before you commit to the crossing.
Do you need permits or special documents to cross?
Yes — this is an international border crossing, so you need valid passports, vehicle title or notarized authorization if the rig isn't in your name, and vehicle import permits for whichever country you're entering. Both the Argentine and Chilean border posts must be cleared during their operating hours, which are limited and seasonal, so verify current hours at pasosfronterizos.gov.ar before departure.
What's the hardest section of the route and what makes it brutal?
The switchbacks climbing to the 15,633 ft summit on the Argentine side are the crux — loose gravel, sheer drop-offs, and altitude-related power loss in naturally aspirated engines hit simultaneously here. Turbocharged vehicles still feel the thin air; drivers and passengers feel it harder, so factor in AMS risk if you're camping at elevation the night before.
Is there any water or fuel available along the 155-mile route?
No fuel exists between Rodeo and Vicuña — fill completely in Rodeo before departure and confirm your range covers 250 km of high-altitude, low-efficiency driving. There are stream crossings with snowmelt water that can be filtered, but carry a minimum of 4 liters per person for the crossing itself.
Trail track
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