Illinois Public Land Survey System (PLSS) boundaries and designations in line and polygon feature classes. The polygon attribute data include meridian, township, range, section and county number (FIPS) designations. The line attributes indicate line type, including the state line, county lines, township and range lines, section lines, Indian treaty boundaries, base lines, principal meridians, and boundaries between areas mapped from different principal meridians. (ISGS, 2003).
THESE DATA HAVE POSITIONAL INACCURACY OF UP TO 600 FEET IN SOME AREAS OF THE STATE. THEY ARE NOT TO BE USED AT SCALES GREATER THAN 1:62,500. THE DATA ARE NOT APPROPRIATE AS A GEODETIC, LEGAL OR ENGINEERING BASE.