Back to Tucson Metro Region main page

  The Tucson"Main" central office serves Qwest as the main regional tandem for the Tucson area and AT&T for long distance and toll services.  The office was originally built by Mountain States Telephone and Telegraph Company (later Mountain Bell) and expanded and modified by US West in the 1980s.  Phoenix became an AT&T Long Lines microwave hub when TD-2 microwave service was introduced in the early 1960s.  Microwave paths from Tucson to southern and southeastern Arizona were "radial", meaning all paths came out of Tucson and there were no connections east into New Mexico.  The only connection Tucson had to the Long Lines network system was the path north that connected into the Phoenix network.  Tucson was a primary center in the AT&T hierarchy switching plan and had a direct trunk group to the Phoenix sectional center.  AT&T introduced #4A service to the office in June of 1974.  Tucson is an international gateway office with direct toll lines into Mexico.  Today the CO has major fiber connections to Nogales, Yuma, Phoenix, Las Cruces and El Paso.