The Churchill River is a river in Newfoundland and Labrador which flows east from the Smallwood Reservoir in Labrador into the Atlantic Ocean via Lake Melville. The river is 856km long and drains an area of 79800km²; it is the longest river in Atlantic Canada.The river is still known locally as Mishtashipu or Mishta-shipu (″Grand River″) by the Labrador Innu and its western section as Patshishetshuanau-shipu by the Central Innu, the peoples of NunatuKavut (Labrador-Metis) and Nunatsiavut, and settlers who identify as Labradorians call it the Grand River.In 1821, Captain William Martin, in command of HM brig Clinker, took it upon himself to name the river the Hamilton River after the then Commodore-Governor of Newfoundland, Sir Charles Hamilton. On February 1, 1965, the river was renamed the Churchill River by Premier Joey Smallwood, in honour of former British Prime Minister Winston Churchill.