Alterac Valley is a battleground in the continuing conflict between the Horde and the Alliance. The two opposing sides are the Frostwolf Clan (led by General Drek'Thar) of the Horde, and the Stormpike Guard (also known as the Stormpike Expedition, led by General Vanndar Stormpike) of the Alliance. Both sides lay claim to this secluded territory.
Long before the start of the First War, the warlock Gul'dan exiled a clan of orcs called the Frostwolf Clan (led by Durotan, father of Thrall) to a hidden valley deep within the heart of the Alterac Mountains for refusing to drink the blood of Mannoroth. It is here in the valley's southern reaches that the Frostwolves etched out a living until the rise of Thrall's new Horde.