A fenced in quarry area that has been flooded, it is found to have scatters of cut stone around it. There are stairways leading up the north side of the quarry and a sloped ramp that extends into the water. The top level on the east side includes an elevator as well as a camper in which Sully Mathis's terminal can be found which details his plans for restoring the quarry for use as a base. There are several campers spread out around the nearby area.
If the water is drained from the quarry during Pull the Plug, 24 hours have passed and one has reached level 12, then Sully will then (when the Sole Survivor next returns) be found to have brought in his gang of raiders, and these hostile raiders will be found spread out throughout the quarry. Sully Mathis will now be found to be much more powerful - minimum level 30 - and like the raiders will henceforth be implacably hostile regardless of any prior help he was given. Three mirelurk pens will also be found in the area.
- Taboo Tattoos issue #2 - In a metal trailer caravan (the one closest to the excavation area) on the south side of the excavation area and directly southwest of the water pump.
- Sully's journal - Holotape in the east trailer inside of a terminal.
- Pull the Plug - Sully Mathis will ask for help to repair the pipes of the water pump and empty the quarry of the irradiated water. After completing the quest and 24 hours have passed (with the player outside the map zone and needs to be at least Level 12), Sully Mathis will be hostile, and be the leader of a raider gang which he initially commented about doing in his terminal entries. However, if he is killed immediately after the end of the quest, that will be that.
- Raider Troubles - Once Pull the Plug has been completed, troublesome raiders might take refuge at this location between two attacks on the Commonwealth settlers.
- Quartermastery - This is one of the many locations Scribe Haylen will send the Sole Survivor to recover a piece of technology.
- The Thicket Excavations 'zone area' is one of a few places in Fallout 4 where an infinite supply of weapons, ammunition, medical supplies, food, water and other junk may be obtained with no respawn delay. After Pull the Plug, the Sole Survivor can return repeatedly and crawl through the area, looting all of the containers and shelves. All of the materials will respawn infinitely with no delay, but the Sole Survivor must move far enough away for the respawn to occur (the railway tracks just south of Starlight Drive In is far enough). This quirk can and will eventually include infinite respawn of raiders and the mirelurks after the raider version of Sully Mathis (or his surrogate) is killed and his corpse has despawned (requires 20 in game days without entering the zone area; this is possible to determine by the "[Cleared]" tag no longer being marked on the map for the location). There is an automated turret that will respawn with the raiders, but may respawn in a slightly altered position with each visit (if destroyed). The obtainable materials in many locations change when Sully Mathis appears with the raiders and mirelurks after Pull the Plug (also, more items appear).
- After the Pull the Plug quest, but before Sully Mathis appears with the raiders, anything left behind in the zone area can be retrieved later. When Sully Mathis and the raiders appear and the zone is marked as "[Cleared]" on the map, anything left behind in the zone area can be retrieved later until the zone area resets. When the zone resets ("[Cleared]" no longer marked on the map), from that point forward anything left behind will be lost as the zone will reset completely and immediately if the player moves far enough away.
- There is a chemistry station part-way down towards the bottom of the excavation area. It is in a little shed on the south side of the quarry.
- At approximately the mid-section of the quarry on the north side, a weapons workbench is accessible.
- The Aquaboy/Aquagirl perk will allow the Sole Survivor to find some very minor loot underwater before completing the Pull the Plug quest. The content of the underwater containers will respawn after completing the quest Pull the Plug.
- The Thicket Excavations' raider camp respawns accordingly to the level of the Sole Survivor as well as the containers at the surface/bottom of the area, but Sully Mathis has a minimum level of 30. The trunk at the bottom does not respawn though, until Thicket Excavations has been drained.
- While the quarry is flooded, the elevator will not function from the surface. Diving into the water while equipped with power armor may not be a good idea. If equipped with power armor, the Sole Survivor may not drown (depending on the Sole Survivor's position within the water), but the Sole Survivor will immediately sink to the bottom of the quarry, unable to 'swim' back up. It is possible to walk around, potentially finding a route using stairways and platforms to make a return to the surface. It is also possible to reactivate the elevator by pressing the button right at the bottom. Wandering along the bottom of the quarry will be very time consuming compared to swimming around and repairing the pipes without power armor. If the Sole Survivor does wind up at the bottom while in power armor, it may just be better to exit the power armor and then come back to the quarry when it has drained. So long as the fusion core is removed and a return trip to the zone area is made within a reasonable period of time, the abandoned power armor will still be there.
- Attempting to place mines after completing Pull the Plug, but before the quarry has drained will not work, in the sense that the mines will all disappear when the zone area resets in its drained form.
- If Piper is present, she may comment, "Goodness! That may be hiding a lot of mirelurks!"
Thicket Excavations only appears in Fallout 4.
- PC Playstation 4 Xbox One Upon arrival at Thicket Excavations, there seems to be a foglike low-res concrete-floor, hovering above most of the real surfaces, and it persists under water. It is the high distance version of the model (aka LOD) one should only see when the object is very far away. This manifests in that both the Sole Survivor and Sully Mathis wade knee deep in concrete, Sully always hovers around the compressor/pump, before the Sole Survivor suddenly falls into the water or the access-way leading down into the excavation. The impact of this bug can be negated by restarting the game. [verified]
- PC Playstation 4 Xbox One If one swims underwater to enter the excavation site before draining it, they will fall down to the floor and be able to walk and shoot their gun underwater. In some cases, Dogmeat may also teleport down to the player character and swim in place as he tries to follow them.[verified]
- PC Xbox One Occasionally, the caged mirelurks will spawn outside of their cages. Caged mirelurks only turn hostile when attacked, or when the Sole Survivor (or a companion) enters their cage, so the mirelurks will roam around without turning hostile. [verified]
- PC Playstation 4 Xbox One Similar to one of the USS Constitution bugs, companions tend to repeat their location-specific comments over and over as long as they are in the quarry's vicinity.[verified]