The first 3 numbers do not necessarily indicate where a card was issued. The first 3 digits indicate where that card holder first signed up for a card. Reissues at any Harrah's would continue to have the original issue number. Example: I first received a Harrah's card in AC (157). I have since received Harrah's cards in at least 10 other Harrah's casinos. Each card was a reissue using the same AC number (157). Do not believe anyone that tries to tell you a card is from such and such location based on the first 3 digits. They will most likely be WRONG.
Paul