The entrance to Gold Dredge #8 in Fox, Alaska is located where part of the Alaska pipeline comes above ground and then goes back under. Here they have put up store boards and a piece of the pipe with a pig in it. I searched the internet for what P.I.G. stood for and found this:
Pipeline Inspection Gauge: Early pigs were made from materials such as straw, barbed wire and leather and made a squealing sound while traveling through the pipes - for this reason, they were eventually called “pigs”. The name eventually became an acronym for “Pipeline Inspection Gauge” or “Pipeline Intervention Gauge”.
Our reasons for coming to this location was to see the gold dredge. At the dredge location we got another surprise when we were handed a bag of pay dirt and shown how to separate the gold from the unwanted materials.... Gold Panning.