Are Mountain Dwarves meant to have different traits from their Hill cousins?
From the SRD:
But that's all it says (similarly for 3.0E).
From the SRD:
....
SUBRACES
The information above is for hill dwarves, the most common variety.
There are three other major dwarven subraces, which differ from hill dwarves as follows.
<snip> description and traits for Deep Dwarves and Duegar </snip>
Mountain dwarves live deeper under the mountains than hill dwarves but generally not as far underground as deep dwarves. They average about 4-1/2 feet tall and have lighter skin and hair than hill dwarves, but the same general appearance.
But that's all it says (similarly for 3.0E).