Close to Mendoza check out Rafting Argentina, they have a web page. They have all kinds of gear and good people working for them. We floated the Rio Mendoza with them last year in November. It was killer, also that is the low water season but still incredible scenery and plenty of water. Those Andes are pretty impressive. I would love to see some of those drainages kickin'. The flood plain is very impressive and straight up on both sides. They actually did all the shuttles and everything else for way cheap. We got picked up at our little villa in Chacras de Coria and brought us back down the mountains in the eve. If in that area check out Pulmary Wines, it's a small family owned vineyard that has fantastic wine and food. Side note- Rafting Argentina has a zipline system that is alot more "hairy" than anything in America de Norte. Worth a look for sure.