Archives at the Institute for Fisheries Research (IFR) hold records of thousands of lake surveys from the University of Michigan and Michigan Department of Natural Resources. The records contained in this dataset are jpeg images of the index card records from the IFR surveys. Images include the front of the card and when available, the back of a card. and Lake Mapping Record Cards contain drawings of lakes with depth contours (bathymetry), as well as other features like bottom substrate, vegetation, and shore features.