Brokenrock Mountains
The Brokenrock Mountains was a set of mountains in Draenor valued by the Orc chieftains during the Second War in the official 
[Blizzard] bonus map for Warcraft II called "Mountain Pass". They were valued for their high amounts of gold ore.
The Brokenrock Mountains were presumably destroyed when the Dark Portal collapsed and tore through Draenor. They are not featured in the Burning Crusade expansion, supporting this assumption.