After getting annoyed by some of the original mountains not working, I decided to have a go at fixing them.
Since my efforts met with success, I'll pass them along for someone else to use.
The rar contains:
Desert Mountains - That actually are
NEW! - Desert Island Mountains - Just like the name sounds.
NEW! - Plains Mountains - For anyone who wants to add Badlands to their Wierd West mod, these have plains grass at their base.
Snowy Mountains - Regular mountains with a snowy/rocky base.
Tropical Jungle Mountains - The desert mountains were used because the sandy base is the same color as the island sand.
And the updated terrain.mes for the new listings.