Ann Arbor’s most famous glacial erratic is “the rock” that sits at the corner of Washtenaw and Hill. This chunk of Canadian limestone was originally deposited by glaciers in a gravel pit off of Pontiac Trail. It was moved to Ann Arbor by then city parks superintendent Eli Gallup in 1932 to become a memorial honoring George Washington on his 200th birthday. Buried in the foundation of the rock is a box describing its history. Originally the rock was painted grey and had a copper plaque in tribute to President Washington. There it sat unchanged until the 1950s when a group of Michigan State hooligans adorned this stone with the letters, “M. S. U.” This graffiti was soon covered up and a tradition was born. In subsequent years it has been painted hundreds, if not thousands of times. A few years ago, one enterprising student took a core sample of the paint and found it to be an inch and a half thick on its top side and five inches on the bottom. My all-time favorite paint scheme occurred at the time that NASA’s Skylab station was falling back to earth. The rock was simply painted silver, with the NASA logo. It looked like molten aluminum.