The Wisconsin Geological and Natural History Survey, as part of the University of Wisconsin-Extension, is "an interdisciplinary organization that conducts natural resources surveys and research to produce information used for decision making, problem solving, planning, management, development, and education". The site offers downloadable online publications such as annual groundwater level summaries and understanding Wisconsin township, range, and section land descriptions. It also contains lists of other publications and various maps of Wisconsin, all of which can be ordered by mail. Information on the history of the survey and an interesting section that includes pictures and descriptions of karst (limestone) development and features is also available.