Utility's been buying, selling since 1873

Puget Energy, whose earliest corporate predecessor dates to 1873, has gone through many corporate changes in the last century.

1873: Seattle Gas Light Company, the earliest predecessor of Puget Sound Energy, introduces Washington Territory to manufactured-gas lighting.

1885: Edison Electric Light Company agents Sidney Z. Mitchell and F.H. Sparling arrive in Seattle to solicit investors in a new Seattle Electric Light Company. The new company begins electric service from a Pioneer Square-based central power-station system — the first of its kind west of the Rocky Mountains.

Late 1880s: More than a dozen power companies operating in Seattle. Many fold after the "Panic of 1983."

1898: Mitchell puts together a deal combining the defunct power companies into Seattle Electric Co.

1898: Region's first large hydroelectric plant completed at Snoqualmie Falls by civil engineer Charles Baker.

1900: The national-utility cartel Stone & Webster controls the Seattle Electric Co. and virtually all of greater Seattle's private electric utilities and street railways.

1912: Stone & Webster incorporates its regional holdings as the Puget Sound Traction, Light & Power Company. Over the next 50 years, it acquires over 150 small utilities across the state.

1919: Puget Sound Traction, Light & Power is reorganized as Puget Sound Power & Light (often called simply Puget Power).

1930: Washington state voters pass a law allowing counties to form public-utility districts for electricity distribution and to condemn property. Puget Power would eventually lose the greater part of its service area to public utilities.

1934: Federal anti-trust regulations dissolve the Stone & Webster utility cartel and Puget Power was reorganized under local ownership.

1952: Seattle narrowly votes to purchase Puget Power operations within city limits. Puget Power lost 40 percent of its revenue and Seattle City Light took control of the city's power needs.

1956: Washington Natural Gas gives region its first natural-gas service.

1997: Puget Sound Energy is created by the merger of Puget Power with Washington Energy Co.

1999: Puget Energy formed as a holding company over the utility.

2005: Puget Sound Energy becomes the first Northwest utility to solely own and operate a large wind-powered facility, at Hopkins Ridge, Columbia County. A second wind facility, Wild Horse, Kittitas County, opens in 2006.

2006: Puget Energy sells Infrastrux Group, launched in 2000 in attempt to diversify into the unregulated business of utility construction services.

2007: Puget Energy's board of directors agrees to sell Puget Energy to a consortium led by Macquarie Infrastructure Partners.