James Bond "Diamonds are Forever" led to creation of the branch!
In 1974 the Nevada branch of the Screen Actors Guild was formed in Las Vegas. In the later 1970s and early 1980s additional branches were formed in Philadelphia, San Diego, Atlanta, Arizona and Houston (http://www.sag.org/).
The Screen Extras Guild had been operating in Nevada since the 1960's with a local, most of that under the presidencies of Carlton and Perry Adair. In 1980, the over 50,000 members looked with interest at a possible reuniting merger with the Screen Extras Guild and with their independent sister, the American Federation of Television and Radio Artists (AFTRA). Meanwhile the negotiating units for management did merge into the Alliance of Motion Picture and Television Producers, against whom SAG negotiates theatrical, meaning film and television, contracts(AMPTP) (http://www.sag.org/).