Wish someone had of posted a pic like this before I climbed to the left in 2002. :)
Thanks to yours and others comments I didn't have to this year. It was a sandtrap on the side of the mountain.
This picture was invaluable! I printed it and took it with me when I went in Nov. 2010. When we got to the point where the picture was taken, the natural way seemed like it should have been to the left (red). Had we gone that way, we would have realized too late that it was completely sandy, and almost impossible to go up.
Really, one of the best pieces of advice one can give about la Malinche. It's incredible how many people go up the "arenal" even after you tell them not to at the foot of it.