Former Bullwhackers in Black Hawk is now owned by the same group that owns Johnny Z's in Central City Colo. and they have a blue Club Z slot card, only one level found so far so let me know if you see anything besides the blue card.

Here's a link to the slot card image on the ChipGuide
http://www.themogh.org/cg_chip2.php?id=COBHZC&p=0001#320