My own personal thoughts. The Riverside is the closest casino to Davis Dam and therefore used that location on its chips (maybe as a tourist draw?), instead of SouthPoint. I believe the owners of the Riverside knew the change of name was coming and ordered new chips with the name Laughlin. This may also have been the time frame that Don Laughlin was becoming a notorious figure in the area and bought out the Riverside. After buying the Riverside the old chips were destroyed or canceled and Don ordered new chips for his casino.