The station premiered on May 5, 1949, producing its shows at the Sutro Mansion and transmitting via a 580-foot-high broadcast tower. Shortly after, KPIX and a television station owned at that time by Metromedia joined them at this facility. The stations eventually moved to their own studios, but continued to transmit their signals from the tower.
In the mid-1960s, Bay Area television stations were receiving complaints of poor reception in many parts of the area. They conceived a project to build a taller tower and a larger transmission building to accommodate most of the stations in the Bay Area. Two sites were considered: the Sutro site and Mount San Bruno. After some investigation it was determined the Mount San Bruno site was too close to the airport for a taller tower, and as a result, the Sutro site was selected.
After years of hearings and litigation, construction of the $4 million Sutro Tower project began in 1971. Sutro Tower was designed by Albert C. Martin & Associates of Los Angeles. At 977 feet high, it was 68% higher than the original broadcast tower. It was fabricated and erected by Kline Towers, a subsidiary of Kline Iron and Steel of South Carolina. Its three legs are embedded in 15 million pounds of cement, and its towers are made of 3.5 million pounds of steel. As part of the stations’ final agreement with the city, the original tower and the Sutro Mansion were removed during the project.
Construction was completed in 1973. The first stations went on-air on July 4, 1973. In 2009, the tower converted to all-digital transmissions.