The Grey Mountains, or the Ered Mithrin, were a large mountain range in Middle-earth to the north of Rhovanion.
In Edain Mod, units of Ered Mithrin are a sub-faction of the Iron Hills. They can be recruited from the Ered Mithrin Bastion built on an Outpost. The fortress can research several upgrades which make it more defensible against enemy attacks, including a mighty catapult. Zealots, Hunters, and Dragon Slayers can also be trained here.