@RustyCrab also maybe stashed in the pipes on the other side of the dam exterior, have to walk across the little ledge and go to the back right. I've found it there several times
and then when you go back into the dam via the window on that side it'll sometimes be leaning on the desk to the left as you enter
the last place I've found it is in the cave below the dam, on the left as you go down the river with rabbits in front of it. often some good starter gear there too, skill book maybe