Long Range Lockpick

This stash is hidden in the Deep North Irrigation Reservoir. Read the note before crossing the bridge. The stash is hidden inside the locked control center. First, you have to climb the ladder and kill the cultist sniper from the shed across the river. You can snipe him yourself or just the zipline to get cross the river and get closer faster.

After getting rid of the enemy, break the boards on the doorway and the window to give you a clear view of the reservoir control room’s window. From there, you have to shoot the lock using a sniper rifle. Hold your breath and aim for the spot as shown in the screenshot below. After successfully doing so, the objective will be updated and you simply need to head to the control room and collect your reward.