World of Warcraft Quests involving Bael'dun Excavator:
The Ranger Lord's Behest Travel to the northern borders of the Eastern Plaguelands and recover the Quel'Thalas Registry. The item is somewhere in the Quel'Lithien lodge.
You must also slay 8 Rangers, 8 Pathstriders, and 8 Woodsmen.
The Barrens Horde Quest
Gann's Reclamation - (Step 1) Gann Stonespire wants you to kill 15 Bael'dun Excavators and 5 Bael'dun Foremen.
Bring Khazgorm's Journal to Gann Stonespire.
Diffusing the Threat Find the Stormpike Explosives Expert and kill him. Return to the Frostwolf Explosives Expert when the task is complete.
Alterac Valley Alliance Quest
Fallen Sky Lords (Alliance) Travel to Frostwolf territory and search for Wing Commander Slidore, Wing Commander Vipore, and Wing Commander Ichman. Return to Commander Duffy should you complete your mission.
Silithus Alliance & Horde
Into The Maw of Madness - (Step 2) Commander Mar'alith at Cenarion Hold in Silithus wants you to find his beloved Natalia. The information that you gathered points to Hive'Regal in the south as being the area in which you may find Mistress Natalia Mar'alith.
Do not forget to visit the dwarves at Bronzebeard's camp before venturing into the hive. They might have some additional work and advice for you.
And [Name], remember the Commander's words: "Do what you must..."