Back in 1970, Mr. Mercat and I camped in the saddle between popo and iota. We were able to see all the ranges in both directions to the Atlantic and to the Pacific. Amazing place.
I know where you are describing. I am trying to remember the name of the pass. Was it The Pass of Cortez?
I was stationed in Mexico City 1991-1993. Our quarters were in the ‘burbs above the bowl of MC. When I went out to run in the clear early morning, often before first light, I could see Popo. It was very dramatic. Clear days were, however, few and far between.