Abra del Acay Pass

At 16,046 feet above sea level, Abra del Acay Pass holds the record as the highest navigable pass in the Americas, and your vehicle will feel every foot of that climb. The 75-mile route from Cachi through Argentina’s Salta province starts in lush valleys but ends on oxygen-starved altiplano where the air is so thin your engine will gasp for breath and you might too. This isn’t a trail for weekend warriors or stock rigs—the gravel switchbacks, loose rock sections, and punishing altitude demand a high-clearance 4WD with good brakes and an engine that can handle severe derating at altitude.

The route climbs 8,200 vertical feet through some of the most remote terrain in northwestern Argentina, crossing landscapes that shift from green valleys to barren moonscapes of volcanic rock and salt flats. May through October offers the only reliable weather window, as winter storms and summer rains make the pass impassable. There’s no cell service, no fuel stops, and precious few places to turn around once you commit to the climb. Plan for one to two days depending on conditions and mechanical sympathy, and carry extra fuel, water, and warm gear—temperatures can drop below freezing even in summer at these elevations. The Administración de Parques Nacionales manages access, though permits aren’t required for the main route.

Dispersed camping is allowed along the route, but finding level ground above treeline becomes a challenge as you gain altitude. The thin air affects both humans and machines—expect significant power loss, overheating issues, and altitude sickness if you’re not acclimatized. Many rigs that handle technical rock crawling at sea level struggle here simply because there isn’t enough oxygen to burn fuel efficiently. The descent is just as punishing on brakes and nerves as the climb is on engines and lungs.

What you get for the punishment is a drive across the roof of South America through terrain that looks more like Mars than Earth, with views across the Puna plateau that stretch to horizons most people never see. It’s a bucket-list accomplishment for serious overlanders, but only if your rig and your preparation match the mountain’s demands. This isn’t about conquering obstacles—it’s about surviving altitude while crossing one of the most remote passes on the continent.