This mod will add 3 Mountains and as for a bonus it will add a bay to your GTA IV
if you want to disable any of the maps you will need to read the Readme for that.

Textures are really HD and IV handled them like a piece of cake

512 to 2048 textures.

Spec and Normal Maps applied to the model.

Maybe I will add some trees later to the mountains in life and if this gets successful of course.