Puget Sound faults about 1100 years ago (AD 900—930) an earthquake of magnitude 7+ uplifted Restoration Point and Alki Point, dropped West Point (the three white triangles in the Seattle Basin on the map), caused rockslides in the Olympics, landslides into Lake Washington, and a tsunami on Puget Sound. It extends as far east as (and probably terminates at) the Rattlesnake Mountain Fault Zone (RMFZ; the southern extension of the SWIF) near Fall City. This seems geologically reasonable, as both the SWIF and RMFZ appear to be the contact between Tertiary Crescent Formation basement of Puget Sound on the west and the older
Puget Sound Energy actually is reduced by—state mandated I-937 energy efficiency programs, adding an average 25 additional "Negawatts" generation capacity per year. For its natural gas service to customers, PSE purchases a portfolio of natural gas supplies originating in western Canada and the U.S. Rocky Mountain states. PSE was formed in 1997 when two of its largest ancestral companies – Puget Sound Power & Light Company and Washington Energy Company – merged. In 2009 Puget Sound Energy was sold to foreign investors led by Macquarie Group, in a leveraged private equity buyout. Puget Holdings, the U.S. title of this group of long-term infrastructure