Trapper’s Key Fragment quest is a part of Fallout 76 Key to the Past
Search for Notes at the Trappers Camp
Next up is the Trapper’s Key Fragment, which you will need to visit multiple locations to obtain. Start by heading to the Trapper’s Camp marked on your map, south of the National Isolated Radio Array. Trapper’s Camp is not a Location, so you won’t be able to warp there and it can be hard to find. I recommend going south of the radio array without heading down the cliffs, then approaching the camp from the west side. This lets you avoid most of the traps set at the entrance.
Once inside the Trapper’s Camp grab whatever loot you want then follow the quest marker to the Trapper’s Note. This note will tell you to go to Huntersville, a town located west of the Trapper’s Camp. Either teleport to a nearby location or follow the road up the cliffs to reach the town.