This quest is not available in game.
Mountaineer Gravelgaw in the southern guard tower wants you to kill 10 Stonesplinter Skullthumpers and 10 Stonesplinter Seers and report back to him.
Mountaineer Cobbleflint had nothing but good things to say about you, <race>. For that reason I am going to entrust upon you a mission of utmost importance. We need to keep pressure on the invading Trogg forces until our Dwarven brethren return from the Alliance front.
Set forth into the southern hills and kill 10 Stonesplinter Skullthumpers and 10 Stonesplinter Seers. Your attacks will buy us some time. Report back when your mission is complete.