Hanson's Bar in Robinson — a town of fewer than 40 people — is now touting its continental bull's-eye status, dismissing Rugby's decades-long claim as the continental nucleus. The debate over North America's geographical center began almost 90 years ago when a respected federal mathematician stuck a pin in a cardboard map of the continent and recorded the coordinates of where it balanced on his finger, said David Doyle, a former chief geodetic surveyor with the National Geodetic Survey. The town enforced its trademark for years, even threatening a legal action in the 1980s when Pierre, South Dakota, tried to stake a claim. Through "barstool science," they have concluded that global warming has melted the polar ice cap, moving the land mass south until North America's centermost spot lies about in the center of their 45-foot-long bar.