This file is a digital geospatial Environmental Systems Research Institute (ESRI) ArcGIS version 9.3 Geodatabase Polygon Feature Class representing land use in northeastern Illinois. Northeastern Illinois is comprised of the counties of Cook, DuPage, Kane, Kendall, Lake, McHenry and Will. Land use is identified to 49 categories (with additional secondary classifications for selected uses), and was created using color orthorectificed aerial photography that was captured in April, 2005; this photography, in addition to other digital sources cited in this document, were used to compare with the previous (2001) Inventory to identify areas of change. The minimum land use classification area size was 1 acre or 2.5 acres (within the City of Chicago 0.5 acre or 1 acre), depending on the type of land use being classified. Land use categories define homogeneous areas and represent features as they appear on the earth's surface. They are not generalized to any other geography. This dataset is projected using the Transverse Mercator map projection. The grid coordinate system used is the Illinois State Plane Coordinate System (Zone Number 1201), NAD83 with ground coordinates expressed in U.S. Survey Feet.