Guarda su Altadefinizione. The short documentary visits the groundhog research center in the Rocky Mountains of Colorado. It was made for Sony Home Entertainment's 15th anniversary edition DVD release of the 1993 film, "Groundhog Day." It was filmed on location at the silver mining ghost town of Gothic, Colorado, near Crested Butte. The Rocky Mountain Biological Laboratory has been located there since its founding in 1928.