The Lamoille River is a river which runs through northern Vermont and drains into Lake Champlain. It is about 85miles in length, and has a drainage area of around 706sqmi. The river generally flows southwest, and then northwest, from the water divide of the Green Mountains. It is the namesake of Lamoille County, Vermont, through which it flows. The river was the basis of the name of the now-defunct Lamoille Valley Railroad Company, successor to the St. Johnsbury and Lamoille County Railroad.
Legend has it that early French settlers named the river La Mouette, meaning "The Seagull". However, a cartographer forgot to cross the t's, which led people to begin calling it La Moulle.[1] Over time, this became Lamoille, elided in speaking.
In July 2023, heavy rains caused flooding on the Lamoille River and on the nearby Winooski River and Missisquoi River.[2]