Ruta Nacional 23 Paso de Sico High Puna Crossing

A stock high-clearance 4WD is the minimum — a Land Cruiser 200 or 4Runner in factory trim can manage the gravel and grades, but aired-down tires and a full-size spare are non-negotiable. The real threat isn't clearance, it's the sustained altitude hammering your engine and your own body. Turbocharged rigs handle the thin air at 4,079m noticeably better than naturally aspirated ones.

May through October is the reliable window — austral winter in the Puna is bone dry and cold, which is exactly what you want on this route. November through April brings summer thunderstorms and flash flooding that can close the crossing for days at a time with zero warning.

Yes — Argentina's Administración Nacional de Parques Nacionales requires documentation for sections crossing protected land, and you must have your vehicle's papers and passport in order for the Chilean border crossing at the far end. Fees are minimal to none for the Argentine side, but border formalities are real and they inspect vehicles thoroughly; carry your full documentation and declare all food.

The stretch between San Antonio de los Cobres and the altiplano plateau is where altitude sickness becomes a legitimate emergency risk — you're climbing to 13,383 feet across 156 miles with no bail-out options and zero cell service. The gravel is generally manageable but corrugated and punishing; the danger is a mechanical failure or a medical issue in a place where help is two or more hours away in any direction.

San Antonio de los Cobres is your last guaranteed fuel stop before you cross — fill every jerry can you have, because there is nothing reliable until you're well into Chile. Water sources exist near some salt flats and quebradas but are inconsistent and require treatment; carry a minimum of 10 liters per person for the full crossing and plan as if you'll find nothing along the way.