I think this is the chip that there was a very long discussion on some time ago. One side argued that they were first used in Las Vegas and then late used at the Sliver Slipper in Edmondton. The other side argued that they were only used in Canada. I think in the end the consinsus was that they were just Canadian chips. Here is a link to ONE of the threads in the Archives:

http://www.thechipboard.com/cgi-bin/tcbarc14/tcbarc14.pl?read=489930