http://images.uesp.net/e/ef/SR-map-Skyrim.jpg
This names all the major mountain ranges.
South = Jerall
East = Velothi
West = Druadach
Would you believe I've never really looked at that map!
I think I missed the mountain names when I did glance at it because they're all so small and squiggly, and merge with the mountains. I'll have to have a closer look!