Western. In particulary, the northwestern part of the state. Numerous lakes, rivers and streams. There's also more trees and less wind than in the southwestern part of the state.
western Montana
The western part of Montana, that's where the Rockies are.
western
Western part of Montana.
Western Montana.
western part
Western MT
Western
The western part of Montana has more mountains than the eastern part.
western
That would be western Montana.
Eastern MT
You would find more mountains in the western part of Montana, particularly in the Rocky Mountains region. The eastern part of Montana is generally characterized by flatter terrain and rolling hills.
Western Montana is all mountains. There are relatively no mountains in the east. The western border of Montana is made from the curvature of a mountain range. There are many National forests here.