It was Caesar's Reno dba Harrahs Casino Reno. I couldn't find one for Vegas operations.

Caesars Entertainment Operating Co., Inc dba Harrahs Casino Hotel Reno will be removing from circulation all Harrahs Reno $100, $25, $10, $5 Slot Tokens and $40, $10, $7 and $2 Silver Strike Tokens. Outstanding tokens should be redeemed from June 1, 2012 through September 28, 2012 at the cashier cages located at Harrahs Casino Hotel Reno 219 No. Center St. Reno, NV 89501.