Big Lake (the curved area in the upper left) on June 15, 2011 during the 2011 Missouri River floods with the Missouri River in the foreground. Big Lake from Fortescue, Missouri after being obliterated on June 26, 2011, in the flood. Big Lake is a village in Holt County, Missouri, United States. The population was 159 at the 2010 census. The village is located on the 646-acre (2.61 km2) Big Lake which is the largest oxbow lake in Missouri. It is also adjacent to Big Lake State Park which has the largest marsh in a state park in the state of Missouri.