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The Commemorative
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The Commemorative Quarter for California

The 2000 Census showed that Sonoma County had a population of 458,614 people. This represented 1.35% of the total population of California, making it the state's 16th most populous county (out of 58 counties).

From the Census Estimates for 2009<1>, Sonoma had a population of 472,102 people. This is an increase of 2.94% since the 2000 Census.

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
2007461,424+0.61%+0.36% since 2006
2006459,783+0.25%-0.34% since 2005
2005461,359+0.6%-0.4% since 2004
2004463,211+1%-0.11% since 2003
2002463,593+1.09%-0.19% since 2001
2001464,454+1.27%+1.27% since 2000
2000458,614The Last Census

Sonoma County had 183,153 Housing Units<2> at the time of the 2000 Census.

The 2000 Census shows that Sonoma County has a total area<3> of 1,768 square miles [4,579 km²]. Of this total, 1,575 square miles [4,081 km²] of the area is land, with the balance (10.88%) being water (192.3 square miles [498.2 km²]).

Using the above population and land area values, Sonoma County had a population density of 291 people per square mile [112.4 people/km²], making it the state's 16th most densely populated county (out of 58 counties).

US Census QuickFacts

The Census Bureau has created documents containing demographic information that are called QuickFacts. A QuickFact that is specific to Sonoma County is available. The QuickFact also contains a comparison between Sonoma and the state of California.

Click here for the Sonoma County QuickFact (QF-06097).

Below are some of the communities that are located in Sonoma County:

(2009 Est)
(2000 Census)
Change in
Santa RosaQF-0670098157,468147,5956.69%
Rohnert ParkQF-066254640,92142,236-3.11%

Below are the counties that adjoin and form the boundaries of Sonoma County. A link to their specific Census QuickFact has been provided.

(2009 Est.)
(2000 Census)
Change in
Contra CostaQF-06013   SE1,041,274948,8169.74%
LakeQF-06033   N65,27958,30911.95%
MarinQF-06041   S250,750247,2891.4%
MendocinoQF-06045   NW86,04086,265-0.26%
NapaQF-06055   E134,650124,2798.34%
SolanoQF-06095   E407,234394,5423.22%

The western boundary of the county is on the Pacific Ocean and the southeastern boundary is on San Francisco Bay.

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U.S. Census Bureau
Census QuickFact for Sonoma County

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>A Housing Unit is a broad term for those places where people live (whether occupied or temporarily vacant), such as a house, an apartment, a mobile home, or an area that is considered as a separate living quarter. Separate living quarters (consisting of one or more rooms) are considered to be those places where people live, sleep and eat separately from others and that have access to the outside (either directly or by a shared hallway).

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<3>The area value has been supplied by the US Census Bureau and it can be different than the geographic boundaries of Sonoma. The value given by the Census Bureau reflects their statistical (or sampling) requirements.

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<4>All Quarter-dollar coin images from the United States Mint.

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