Fallout 76 Black Site Guard Key Location Guide

The Blacksite Guard Key is a special key in Fallout 76 that unlocks the locked rear entrance of the Sugar Grove intelligence facility, leading to the Blacksite, the Somnus division. Sugar Grove sits in the Savage Divide. The front entrance opens normally, but the rear passage is blocked by collapsed structure, so the Blacksite Guard Key is needed to open that locked door and enter the hidden area. The Blacksite is a separate explorable area inside Sugar Grove containing extra supplies, holding cells, and their corresponding keys. Exploring it is not required to complete Sugar Grove's main objectives, but players who want to collect every item in the area or explore the Somnus division still need to find this key.

Purpose of the Blacksite Guard Key

The front entrance of Sugar Grove sits on the north side of the building. After entering, players can reach the office area and the SigInt terminal inside the main facility and complete the related quest objectives. The Blacksite Guard Key corresponds to the separate entrance at the rear of the building. Once the locked door is opened with the key, the Somnus division, the Blacksite area, becomes accessible. This area connects to Sugar Grove's main office facility but remains relatively self-contained, with its own exploration routes and collectibles. The Blacksite Guard Key is not a master key to all of Sugar Grove, and it does not directly affect main quest progress. Its main purpose is to unlock the rear Blacksite entrance and open up the extra exploration content.

Where the Blacksite Guard Key Is

The Blacksite Guard Key is in the server room inside Sugar Grove. Enter through the facility's front entrance and follow the internal stairs down to the next floor.

Route to the Server Room

• Enter Sugar Grove through the front entrance and pass through the office area near the entrance. The facility is defended by turrets and robots, which can be cleared or bypassed depending on your equipment and combat ability.
• Continue along the interior corridor. At the stairs, turn left and go down to the next floor.
• Continue along the corridor, pass the Sugar Grove facility logo and another set of stairs, then go down again. At the bottom, turn right immediately into the room filled with computer equipment; this is the server room.
• Inside the server room, head to the far back-left corner. Check the overturned wooden box on top of the computer station; the Blacksite Guard Key sits inside.

Location note: The key is inside the overturned wooden box deep in the server room, not in the toolbox near the room's entrance. Watch for the Mole Rats that appear in the room while you search, and avoid being attacked as you look for the item.

Cell Keys Inside the Blacksite

After obtaining the Blacksite Guard Key, return to the locked entrance at the rear of Sugar Grove and unlock it to enter the Blacksite. Once inside, head down the stairs to reach a room lined with televisions. Then pass through the broken opening in the wall into the adjacent room. On the table in that room are four cell keys:

• A6-KH
• 89-AX
• B2-RS
• V5-XF

Each key opens a different cell door inside the Blacksite and can be used to explore the sealed areas further and collect the items within. Note that W9-FZ is not inside the Sugar Grove Blacksite; it is found in Huntersville. When collecting the cell keys, keep each key's location straight to avoid confusing Huntersville's contents with the items inside the Blacksite.

Related Quests and the Blacksite Guard Key

Sugar Grove is tied to two quest lines in Fallout 76: the Enclave quest line and the Mistress of Mystery quest line. During both, players travel to this intelligence facility to investigate its research equipment, access specified terminals, or collect the data the quest requires. The two quest lines have different objectives, but the relevant areas all sit within reach of the front entrance, so neither requires opening the rear Blacksite entrance nor obtaining the Blacksite Guard Key in advance.

One of Us (Enclave Quest Line)

One of Us is issued by MODUS in The Whitespring Bunker and belongs to the Enclave quest line. Players travel to Sugar Grove, access the SigInt terminal inside the facility, and complete the required steps. The quest's main objectives sit in the area reachable from the front entrance, so it does not require the Blacksite Guard Key or entry into the rear Blacksite.

Prototypical Problems (Mistress of Mystery Quest Line)

Prototypical Problems belongs to the Mistress of Mystery quest line. Players travel to the SigInt research area of Sugar Grove to collect EMP data. That research area is reachable through the front entrance, so completing the quest does not require opening the Blacksite rear door, and the Blacksite Guard Key does not change the quest's normal route.

Frequently Asked Questions

Is the Blacksite Guard Key required to complete the Sugar Grove quests?

No. The key mainly opens the rear Blacksite entrance of Sugar Grove. Both One of Us and Prototypical Problems can reach their main objectives through the front entrance.

The Blacksite Guard Key unlocks the Blacksite area at the rear of Sugar Grove. Players enter the server room inside the facility, find the key in the overturned wooden box deep in the room, then open the locked rear entrance. Inside the Blacksite, four cell keys—A6-KH, 89-AX, B2-RS, and V5-XF—open different cell doors. W9-FZ is found in Huntersville and is not part of the Blacksite's collectibles. Once collected, the key stays in the character's inventory and is not consumed when the rear door is opened, so players can keep it after exploring the area without returning to the server room.