First off, there is a chip like this one on EBAY and seller listed it as "rare."
So, after looking at my traders picked up in the hot and heavy trading room, I discovered I had traded for one.
Searching the Chip Guide, I could not find an entry for Station Casino, St. Charles, MO.
However, I did find a key chain with St. Charles, MO on it listed in Kansas City. and a deck of cards on EBAY using the Station Casino, St. Charles, MO logo.
The $5 chip is a Millennium chip and it could have had a short life on the tables or it somehow was pulled after some reshuffling of that casino.
Any details would be greatly appreciated.