Thumb Lake, also known as Lake Louise by the "Lake Louise Camp" community, is a kettle lake located in Hudson Township, Charlevoix County, Michigan, United States. The epithetThumb Lake derives from the lake's bathymetry. An islet protrudes from the lake's west basin. The total surface area of the lake is 484 acres (2.0 km2), with maximum depths of 152 feet (46 m).
The misnomer "Lake Louise" comes from a former Camp director who wanted to rename the lake after his wife.