Unless someone were to physically go there and verify the chips actually in use;
http://www.themogh.org/cg_chip2.php?id=NVLVCC

There is no reference to a Sparks location in The Chip Guide. When did they open?

I question some of the chips being automatically attributed to Las Vegas by submitters who are taking for granted they are Las Vegas issues without personal knowledge with the notation "Not In TCR". TCR only lists Nevada chips. I have personally documented the chips from Atlantic City in my A.C. catalogs for many years now. Could they have been used in AC and LV? Of course.