This is a rough guess. But i'm like 60% sure these two mountain ranges are the same but from completely different angles. Top shot is that Mystery Desert, and by the looks of it, the foggy shot is likely the Marsh, unless you think that's wrong? So the Desert could be on the opposite side of the water/lake looking North...
So then, that mean's there has to be a mountain on the map between them. And geologically, from those angles, this is the best match i could find. What d'ya think? Preferably i'd like more evidence, but you work with what you got right? Unless someone can find this Mountain Range in other shots, that would be great!