Origins of the name are uncertain but it is alleged to be a reference to the dairy farmers who used to cross this channel by boat to sell their milk in Manhattan markets . Some people believe that the channel got its name because crossing it was so rough that the farmers ' milk was churned into butter by the time they reached Manhattan . According to another legend , before the channel was dredged to accommodate cargo ships , cows were walked across it at low tide to graze on Governors Island . In his newspaper articles about Brooklyn history , Walt Whitman wrote of a time " as late as the Revolutionary War ( when ) cattle were driven across from Brooklyn , over what is now Buttermilk Channel , to Governor 's Island . " In the bitter volcanic winter of 1817 — the volcanic winter following the " Year Without a Summer " — when the thermometer dropped to , the waters of the Upper Bay froze so hard that horse-drawn sleighs were driven across Buttermilk Channel to Governors Island
Year Without a Summer
Year Without a Summer
Buttermilk Channel