We chose the crossing from Lonquimay to Pino Hachado because it traverses a large forest of the araucarias. There is a paved crossing about a hundred and fifty miles south in the lake district, but it is beyond the range of these rare trees. The Araucaria, which is now protected under national law, has long been a symbol of indigenous resistance and tenacity here. Families still harvest the "cabezas" (heads), which are actually a cone containing hundreds of piñons which are like a pinenut, but about 4 times as big. As we slowed to cross a wooden bridge near the Volcano Lonquimay we heard voices calling to us from in the trees. This young girl's brother was up a large tree harvesting cabezas like this one. They try to sell them to the rare traveler along this route.
There is about 25 miles of unpaved road near Loquimay and another 25 miles or so right at top of the pass, but they are working on that road and within a year or two, I think it will be all paved. 
The Lonquimay volcano in the background. Karen zoomed in to show the snow on top. (below)
The Argentine border above, and Argentine Customs below (note the bullet hole in the Aduana sign).
There were still a few rough spots on the Argentine side.