Malpass Library has over 150,000 printed maps of the United States and other countries, including topographic maps for most areas of the United States. However, even mapping has gone digital. Using a Geographic Information System (GIS), it is possible to link data about an area, such as its population, income and education, to digital data showing geographic boundaries and produce a map. Topographic maps have been scanned and georeferenced (aligned with a known coordinate system) for use with a GIS. The following resources can be used to view and download digital topographic maps. To find the map that covers a particular area, use the Geographic Names Information System (GNIS).
Aerial photography is also useful for learning about land use and land cover. In many large metropolitan areas, tax assessors use aerial photography to evaluate property value to determine if changes have been made to a property which means that it should be taxed at a higher rate. Historical aerial photography can be used to learn about early land use and land cover. The following sites can be used to find aerial photography for Illinois and other areas of the United States.