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The Commemorative
Quarter for
The Commemorative Quarter for California

Time Zone: Sonoma County lies in the Pacific Time Zone (PST/PDT) and observes daylight saving time.

The community of Santa Rosa is the Seat for Sonoma County.

Sonoma County is one of the original counties of California and was founded in 1850.

From the Census Estimates for 2009, <1> Sonoma had a population of 472,102 people. This is an increase of 2.94% since the last Census (which gave a population of 458,614 people in 2000).

At the time of the 2000 Census, Sonoma represented 1.35% of the total population of California, making it the state's 16th most populous county (out of 58 counties).

The following table shows the recent changes in population. Other than 2000, the population counts have been estimated by the Census Bureau.

Since 2000
Year-to-Year Change
2010483,878+5.51%+2.49% since 2009
2009472,102+2.94%+1.22% since 2008
2008466,424+1.7%+1.08% since 2007
2000458,614The Last Census

More information can be found on the Sonoma County Census Page for Sonoma County.


Below are some of the communities located in Sonoma County (for more communities, please visit our Nearby Page for Sonoma County):

Community 2009
(2009vs. 2000)
Santa Rosa   157,468147,5956.69% increase  
Petaluma   55,17854,5481.15% increase  
Rohnert Park   40,92142,2363.11% decrease  
Windsor   25,61922,74412.64% increase  
Healdsburg   11,14310,7223.93% increase  

Websites for Sonoma County

Official Website:   www.sonoma-county.org/

If you know of a history or genealogy society whose interest includes Sonoma County, would you please send us the URL for their website? We would like to add their link to our Gazetteer. To contact us, please visit our Feedback Page.

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Footnotes ...

<1>On a yearly basis, the US Census Bureau creates an estimate of the county's population. Keep in mind that this is an estimate and not an actual count. The last physical count was the 2000 Census and the next count will be for the 2010 Census.

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<2>All Quarter-dollar coin images from the United States Mint.

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