At 3,832 metres, the old pass between Argentina and Chile is one of the high points of South American riding, in more than one sense. It is a bare saddle of rock and scree on the border, with thin air, a hard wind and a statue of Christ the Redeemer standing on a plinth, arm raised, facing both countries. The monument was erected in 1904 to celebrate a peace agreement between the two nations after a long dispute over their frontier, and the bronze figure has been a symbol of friendship ever since.
Most traffic now goes through the long tunnel beneath the mountain, which opened in the 1980s and is a fixed link on the Mendoza to Santiago route. The old road over the top is a far smaller affair, rough and steep, and it is usually open only in the warm months and when conditions allow. It climbs from the Argentine side in a series of tight turns on gravel and broken tarmac, with steep drops and little protection. Check the status before you try it, and expect to turn back if snow or wind makes it unsafe. The Chilean side drops through a famous sequence of switchbacks, known as Los Caracoles, on a better road that connects to the Aconcagua valley.
The history is as high as the pass. In 1817, General José de San Martín led his Army of the Andes through passes near here to attack the Spanish in Chile, an extraordinary feat of logistics through snow and cold, with thousands of men, mules and cannon. The route was part of the campaign that led to Chilean independence, and the memory of it runs through both countries.
Uspallata on the Argentine side and Los Andes on the Chilean side are the places to fill the tank. Border formalities can take hours at the tunnel, particularly in summer and at weekends, so bring documents for you and the bike, patience and some food and water.
The cold is brutal even in summer, and the wind can knock a bike sideways. The best conditions are a still, clear morning, when the peaks around you stand out with total clarity.