The points were extracted from the Resources Inventory for the Upper Mississippi River, 1984. A point is a 0-dimensional object that specifies geometric location. One coordinate pair specifies the location. Points represent features like named places. They have no length and are defined as a single x,y coordinate pair.
Lines represent linear features like railroads.
Polygons represent features like counties or lakes and are defined as a string of x,y coordinate pairs with the same beginning and ending points. These attributes are stored in Feature Attribute Tables. The feature attribute table contain information about and values for a particular record. An INFO table specifies the format for each record in the data file and is referred to as the Items Definition. Although these data have been processed successfully on a computer system at the EROS Data Center, no warranty expressed or implied is made by the SAST or USGS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.