Description: This file is a digital geospatial Environmental Systems Research Institute (Esri) ArcGIS polygon feature class of the tile index for Cook County, Illinois. Each tile is 2,500' on a side, and covers an area of 6,250,000 square feet or 143 acres. There are a total of 5,347 tiles, and each tile represents the boundary or extent of each ortho image. This dataset includes a coordinate based tile identification number, a delivery area number, and a project tile category. The delivery area numbers and project tile attributes are a proprietary classification that are unique to this project. This dataset is stored within an ArcGIS 10.8 geodatabase. This dataset is projected using the Transverse Mercator map projection. The grid coordinate system used is the Illinois State Plane Coordinate System, East Zone (Zone Number Zone 3776, FIPS 1201), NAD83(2011) (horizontal datum), with ground coordinates expressed in U.S. Survey Feet.