The first official trek to Gobbler’s Knob to celebrate Groundhog day was in 1887, although Punxsutawny has celebrated groundhog day since the early 180’s. Legend has it that if Phil (the groundhog) sees his shadow, there will be six more weeks of winter. The tradition has followed to find out the prediction, every February 2nd.
The Groundhog day has become a very popular festival in recent years and there is quite a bit of information surrounding the event.
The Official Punxsutawny website. The Official Pennsylvania State – Groundhog Day page.