Rate Map

I have a rates map from the Central Freight Assn. Territory Eastbound Freight Rates. I have no copyright date on the map. But lists Railroads like the M.C & S.S.M./C.G.W./C.C.C. & St.L./C. & A./ P.C.C. & St.L. I bought the map at an Estate Sale. Does anyone have any ideas on the age. It says that is Map 3. My estamation is roughly 1940-1950? E-mail me at behr1208@selectemail.net. Thanks for everyones help.

Chicago & Alton reference would infer pre-1931.

(Most of those rascals have a copyright & date in very small font in the margins or buried in the title near the printers name.)