The dog tag for Hammerhead can commonly be found on the ‘C’ flag on the NorthEast side of the generators tucked away behind a few boxes.
A dog tag can be located at the WNW side of the D flag. Make your way to the double stacked portable units and continue west. find the old beater car near a fence that is partially plowed in and search the driver side seat for the white box. You will need to crouch or be prone in order to knife the box without frustration.
One of the more common locations the tag will spawn is on the rear of the truck with tree trunks loaded onto the back of the bed. You will need to climb onto the pile of logs near the truck bed and jump down onto the platform.