Ruta de los Seismiles Norte — Paso Pircas Negras to Fiambalá via the Puna de Atacama Volcano Corridor

Paso Pircas Negras sits at 4,163 metres on the Argentine-Chilean border in La Rioja Province — but that’s not even the high point. The track north toward Fiambalá through the Puna de Atacama corridor threads past volcanic peaks well above 6,000 metres, skirting thermal fields, dry salt flats, and sand dunes that would feel at home on Mars. This is the northern sibling of the famous Seismiles route run from Fiambalá toward Paso San Francisco — same savage altitude, same lunar landscape, same requirement for total self-sufficiency. The Argentine side drops you through Vinchina and the Famatina Range before the final descent into the Fiambalá valley where peaches grow and the air has enough oxygen to remind you you’re still alive.

Altitude sickness is the primary hazard here — acclimatise in Chilecito or Fiambalá for at least two days before going up. You need a capable high-clearance 4WD with good fuel range; the nearest reliable fuel is Fiambalá to the south or Vinchina to the east, and the crossing sits 300-plus kilometres from either. Best window is November through March; outside that storms can close the pass for days without warning. No formal permit but notify Argentine border control (Gendarmería) before departure. Carry 20-plus litres of water, a sat phone, and cold-weather gear regardless of the season — temperatures swing 30°C in a day up here. The payoff is a genuinely remote high-Andean traverse with almost no traffic.