On 14 November 2007 we re-crossed the Andes by bus from Puerto Varas on Lake Osorno, Chile to Bariloche, Argentina. The route took us through the Parque Nacional Puyehue, right be the southern flank of Volcan Puyehue. That is the volcano that erupted on 11 June, and yesterday shut down air travel here in Tasmania.
Here’s a map of the route across the Andes. For orientation, we were on RA231 on the Argentina side of Andes .