“Ther once was a base called Mather AFB and the flyers out of there had a shoulder patch that said Air Training Command Headquarters West. At the time I think only two ATC bases were west of the Mississippi (Williams In Tempe, now also gone, and Mather itself).”
I’m not sure what timeframe this might have been. I know Mather was still training Nav’s when I graduated college in ‘89, but there are numerous ATC bases west of the Mississippi.