1970 PG&E agreed to construction of up to 6 additional generation units (5,6,7,8,9,&10), each with 55MW capacity.The Geysers was on its way to becoming one of the major geothermal fields of the world. Units 5 and 6 are shown in photo below.

(Photo courtesy Ted Wilmsen)

1974 PG&E entered into steam purchase agreements with GRI and Signal Oil. Sun Oil, Geothermal Kinetics and McCullough Oil Company all acquired diverse lease positions and prepared to drill.

1974 PG%E Unit 11 goes online

         Burmah Oil Company acquired Signal's holdings.

         Drilling depth now routinely reached 7000 or 8000 ft.

B.C. McCabe in 1974 (Photo courtesy Ted Wilmsen)

1978 - 1979 Northern California Power Agency contracted to buy steam
        from Shell Oil.

        Sacramento Municipal Utility District entered into a steam purchase 
        agreement with Aminoil USA (successor-in-interest to Burmah)

        Burmah Oil Company acquired Signal's holdings.        

        California Dept of Water Resources contracted with MCR Geothermal Corp.
        for steam from its Bottle Rock leasehold.

1979 PG&E Units 12 and 15 go online.

        Occidental Geothermal began drilling on its leasehold acquired in the 1979
        federal lease sale.