San Jose, CA
·Pacific Bell - SBC
It was the Bell Telephone Company from its founding on July 9, 1877 until its merger with the New England Telephone and Telegraph Company on Feb. 17, 1879. The merger produced the National Bell Telephone Company, with headquarters in Boston, MA, and the International Bell Telephone company, with headquarters in Brussels, Belgium. On March 20, 1880, the National Bell Telephone company entered further mergers to form the American Bell Telephone Company. On Dec. 30, 1899, the National Bell Telephone Company transferred its assets to a subsidiary called, American Telephone & Telegraph Company. At this point AT&T became the owner of the Bell System; including the Bell logo.
It appears that Sunset Telephone and Telegraph covered Washington in the later years of the 19th Century, but it isn't clear that they were a part of the Bell System prior to the 1917 acquisition by Bell's Pacific Telephone and Telegraph.
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum