California never had the large Italian pools of immigrants to draw a borgata from. The pickings were slim compared to the eastern families. Thats the primary reason. And the WC lacks the "Italianate' flavor the east coast has. another reason for less of a draw
San Francisco, San Jose and Los Angeles had families at one time, with the LA family reportedly still functioning, albeit barely. So did Denver, with a crew in Pueblo. So there must have been large enough Italian populations in these regions to form families
Vegas was key in depleting the west coast mafia families. The money train moved there and anyone who was anyone moved there and began working with Chicago, Kansas City, Detroit, Cleveland etc, not just Italians but the white protestant racketeers, City Hall gang, etc. What was left of the California mafia families dabbled in the drug game but eventually just moved into legitimate business and assimilated with middle class American life.
