Lacolle is a municipality in southern Quebec, Canada, located in the administrative area of the Montérégie, on the Canada–United States border. The population as of the Canada 2021 Census was 2,708. The Lacolle River runs eastward through the middle of the town and empties in Richelieu River. More people cross the border illegally from the Unite…Lacolle is a municipality in southern Quebec, Canada, located in the administrative area of the Montérégie, on the Canada–United States border. The population as of the Canada 2021 Census was 2,708. The Lacolle River runs eastward through the middle of the town and empties in Richelieu River. More people cross the border illegally from the United States there than at any other point. Almost nineteen thousand people were detained in 2017. The nearest town across the border is Champlain, New York.