Here are suggestions to clean-up the list and map of IDOT yards that was based on RR license information...
ARNOLD - Is a license for St. Louis area operations on Missouri radio towers; not IDOT yard
CLAY CITY - Radio Tower Site only, not IDOT Yard
COBDEN - Radio Tower Site only, not IDOT Yard
DUPO - Site of a low power Traveler's Information Transmitter only, not IDOT yard
EAST ALTON = "Wood River" yard
EAST SAINT LOUIS = "Bowman Shed" yard
EDWARDSVILLE - Radio Tower Site only, not IDOT Yard
FARMINGTON - There is a radio tower here for sure, and a very small shed. Not really an IDOT yard.
KINGSTON - Radio Tower Site only, not IDOT Yard
MAHOMET - Radio Tower Site only, not IDOT Yard
MARINE - Site of a low power Traveler's Information Transmitter only, not IDOT yard
MARKHAM This is the "I-57" Yard, and South Side Sign Shop.
MARYVILLE - If somebody can find something in this town I would like to know about it!
MASCOUTAH - Site of a low power Traveler's Information Transmitter only, not IDOT yard
OHIO - Radio Tower Site only, not IDOT Yard
PEERLESS PARK - Is a license for St. Louis area operations on Missouri radio towers; not IDOT yard
PONTOON BEACH - There is no IDOT yard there
SAINT CHARLES - St. Charles, IL is an IDOT yard, however, the Saint Charles, Missouri license
listed in RR allows IDOT operations on a Missouri tower.
There is not an IDOT yard at the geo coordinates associated with this license.
SCAUMBURG - Schaumburg is the IDOT District 1 Headquarters
SCHAUMBURG - Also in Schaumburg is the "Rodenburg Yard" on Rodenburg Rd at Elgin-O'Hare Expwy.
SPARTA - Site of a low power Traveler's Information Transmitter only, not IDOT yard
Terre Haute - License to operate on a tower in Indiana, no IDOT yard there
Thornton - There is no IDOT yard in Thornton
TOWN AND COUNTRY - Is a license for St. Louis area operations on Missouri radio towers; not IDOT yard