There is indeed a path through the mountains. It’s not too hard to find if you’re running past it.
When you’re in Hillsbrad, follow the road back to Thoradins Wall, which separates Hillsbrad from the Arathi Highlands. While on the Hillsbrad side follow the wall North East to the mountains. Then follow the mountains and you’ll soon see a pass through them. It is indeed behind the Durnhold Keep.
Quote:
You can get there from Hillsbrad. There is a valley to the ENE of TM behind the keep full of syndicate folk. It's usually guarded by a couple of named griffons. Straight on through to the other side.
You’ll come across some spiders and bears before you reach the pass, but there aren’t any mobs on the other side of the pass for some distance. I’ve taken this path numerous times with both alliance and horde characters and I’ve never been attacked by a griffon. There is often a wild griffon wondering the area just before the pass, but it’s yellow to both alliance and horde. So it won’t attack you unless you attack it.
On the other side of the pass you’ll find a road. This road will lead to an area held by dwarves. These dwarves will not attack alliance characters but they will attack horde characters. But you can easily enter the valley without getting near any of the dwarves.
The valley is filled with all kinds of mobs. The wolves and owlbears are hostile to everyone. The many griffons in the area are friendly to the alliance but they will attack members of the horde. There are also several troll camps that are hostile to both alliance and horde. Alliance characters can use the dwarven keep as a base of operations. Horde characters will have to run the length of the zone and enter the beach, filled with level 48 to 50 hostile turtles, to reach the horde outpost there.