Take this explanation for what it is worth. MSS & Fremont are Union, Cal, another Boyd hotel is not. I got an explanation from a long time employee. About 30 years ago there was a major strike at the Cal that went on for a very long time. The Union finally gave in, but one of their conditions to settle was that all the replacement workers be fired. The company refused. Some workers returned, some didn't. So now, you have a staff of long term employees who see no need for a Union. True or not, I don't know, but it is a plausible explanation.