Dhurlga - Quarry. Located inside the building that houses the portable power source. It appears once you have activated the generator that powers the conveyor belts and transported the power source out of the building.
Dhurlga - Quarry. Once you have made it to the top of the opposite side of the quarry, the Dhurlga reappears as you approach the exit gate with the power source.
Dhurlga - The Mines. Appears on the wooden walkway section of the area you explore to activate the door that leads you to the platform where you can switch on the ventilation system.
Dhurlga - Underground Research Facility - Basement. In the room that has the elevator that leads down to the final area. The Dhurlga appears after you have activated the elevator.