Black Rock Quarry Control Map. You want to start at the Quarry Entrance. Once you reach the elevator going to the quarry you will notice it is broken.
Where is Black Rock Processing in Control. Case Files - Albany Summary. If the quarry is marked yellow instead of white then itll be the right place if not then itll be somewhere else.
Took me forever to realize that the Cen.
On the next page of Control guide you will find a walkthrough of the task Threshold. Where is Black Rock Processing in Control. Either levitate through the hole or launch a nearby forklift to blow up the wall. In the corridor north of the entrance to the quarry go down the back path and avoid the entity then go to the dead end to find the collectible.