West of Mendoza the plain is left behind and the road starts to climb into dry foothills along the Mendoza River, passing reservoirs, dams and the old spa settlement of Cacheuta, famous for its thermal springs. Here the landscape turns to rock: striped red, ochre and grey hills, with cactus and thorn scrub. Potrerillos is a popular weekend lake for the Mendocinos, with a reservoir used for sailing and rafting, and the road follows its shore with easy, fast curves.
The nearest city is Mendoza, thirty-five kilometres back, and while small shops and a few fuel stations serve the area, supplies are modest and prices higher. If your tank is below half, there is no reason to take chances, and a stop in the city or a small town on the way is smart. Food at roadside stands is basic but decent, with empanadas and grilled meat a good choice.
Route 7 here is a busy road, one of the main trade links between Argentina and Chile, and heavy trucks ply it constantly. That adds a bit of challenge, since passing space is limited and a slow lorry can hold you for miles. On the other hand, the road is well surfaced, the curves are smooth and the gradients are moderate, and the views of the barren canyon walls are excellent. Tunnels and narrow sections need attention, particularly in the afternoon wind.
This section is also dry country for most of the year, with little rain, and the sun beats down, so hydration is important. In winter and spring there can be snow at higher altitudes, and ice on the shaded corners, so check conditions. The best months are late spring and autumn, when the temperatures are moderate. Early morning light turns the rock layers a deep rose colour, and if you see condors turning on the thermals above the cliffs, you are looking at one of the symbols of the Andes.