Editing Sonoma County, California (section)

==Geography==
[[File:Hoodmtndown.jpg|thumb|250px|left|[[Hood Mountain]] with [[vineyard]]s in foreground]]

According to the [[U.S. Census Bureau]], the county has an area of {{convert|1768|sqmi}}, of which {{convert|1576|sqmi}} is land and {{convert|192|sqmi}} (10.9%) is water.<ref name="GR1">{{cite web|url=https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.html|publisher=[[United States Census Bureau]]|access-date=April 23, 2011|date=February 12, 2011|title=US Gazetteer files: 2010, 2000, and 1990}}</ref>

The county lies in the [[California Coast Ranges|North Coast Ranges]] of northwestern California. Its ranges include the [[Mayacamas Mountains|Mayacamas]] and the [[Sonoma Mountains]], the southern peak of the latter being the prominent landform [[Sears Point]]. The highest peak in the Mayacamas within the county and the highest peak in the county is [[Mt. Saint Helena]]. It has uncommon occurrences of [[pygmy forest]], dominated by [[Cupressus pygmaea|Mendocino cypress]]. The highest peak of the Sonoma Mountains is [[Sonoma Mountain]] itself, which boasts two significant public access properties: [[Jack London State Historic Park]] and [[Fairfield Osborn Preserve]].

The county includes the City of Sonoma and the [[Sonoma Valley]], in which the City of Sonoma is located. However, these are not synonymous. The City of Sonoma is merely one of nine incorporated cities in the county. The Sonoma Valley is just the southeastern portion of the county, which includes many other valleys and geographic zones, including the Petaluma Valley, the [[Santa Rosa, California|Santa Rosa Plains]], the [[Russian River (California)|Russian River]], the [[Alexander Valley AVA|Alexander Valley]], and the [[Dry Creek Valley AVA|Dry Creek Valley]].

Distinct habitat areas within the county include oak [[woodland]], [[Sequoia sempervirens|redwood]] [[Northern California coastal forests (WWF ecoregion)|forest]], [[northern coastal scrub]], [[grassland]], [[marsh]]land, oak [[savanna]] and [[riparian zone|riparian woodland]]. The [[California oak woodland]] in the upper [[Yulupa Creek]] and [[Spring Creek (Sonoma County, California)|Spring Creek]] watersheds in [[Annadel State Park]] is a relatively undisturbed ecosystem with considerable [[biodiversity]]. These forested areas have been characterized as some of the best examples of such woodlands.<ref>{{cite web|url=http://www.parks.sonoma.net/Annadel.html|archive-url=https://web.archive.org/web/19971011174618/http://www.parks.sonoma.net/Annadel.html|url-status=dead|archive-date=October 11, 1997|title=Annadel State Park|work=Parks and Recreation in Sonoma County}}</ref> An unusual characteristic of these forests is the high content of undisturbed prehistoric [[bunchgrass]] [[understory]], testifying to the absence of historic [[grazing]] or other [[agriculture]].

Trees of the oak woodland habitat include [[Arbutus menziesii|Pacific madrone]], [[Pseudotsuga menziesii var. menziesii|Douglas fir]], [[Quercus agrifolia|coast live oak]], [[Quercus garryana|Garry oak]], and [[California laurel]]. Common understory plants are [[Heteromeles|toyon]], [[Toxicodendron diversilobum|poison oak]], and, at the fringes, [[Garrya elliptica|coast silk-tassel]].

===Climate===
[[File:DryCreekValley.jpg|right|thumb|Sonoma County's Dry Creek Valley]]

Sonoma County, as is often the case with coastal counties in California, has a great degree of climatic variation and numerous, often very different, microclimates.<ref>{{cite web |url=http://cesonoma.ucdavis.edu/hortic/sonoma_county_climate.pdf |title=Sonoma County Climatic Zones |access-date=November 30, 2007 |publisher=University of California Cooperative Extension |archive-url=https://web.archive.org/web/20070812154328/http://cesonoma.ucdavis.edu/hortic/sonoma_county_climate.pdf |archive-date=August 12, 2007 |url-status=dead  }}</ref><ref name="ucDavisClimate">{{cite web |url=http://cesonoma.ucdavis.edu/hortic/pdf/climate_location_data.pdf |title=Climate data for various locations in Sonoma, Napa, Mendocino, Lake and Marin counties, California |first=Rip |last=Forrey |access-date=November 30, 2007 |publisher=University of California Cooperative Extension Sonoma County |archive-url=https://web.archive.org/web/20070630163510/http://cesonoma.ucdavis.edu/hortic/pdf/climate_location_data.pdf |archive-date=June 30, 2007 |url-status=dead  }}</ref> Key determining factors for local climate are proximity to the ocean, elevation, and the presence and elevation of hills or mountains to the east and west. This is in large part due to the fact that, as throughout California, the prevailing weather systems and wind come normally from the Pacific Ocean, blowing in from the west and southwest, so that places closer to the ocean and on the windward side of higher elevations tend to receive more rain from autumn through spring and more summer wind and fog. This itself is partly a result of the presence of high and low pressures in inland California, with persistent high summer temperatures in the [[Central Valley (California)|Central Valley]], in particular, leading to low pressures, drawing in moist air from the Pacific, cooling into damp cool breezes and fog over the cold coastal water. Those places further inland and particularly in the lee of significant elevations tend to receive less rain and less, in some cases no, fog in the summer.

The coast itself is typically cool and moist throughout summer, often foggy, with fog generally blowing in during the late afternoon and evening until it clears in the later morning becoming sunny, before repeating. Coastal summer highs are typically in the mid to high 60s, warming to the low 70s further from the ocean.

Certain inland areas, including the Petaluma area and the Santa Rosa Plain, are also prone to this normal fog pattern in general.<ref name="ucDavisClimate" /> However, they tend to receive the fog later in the evening, the fog tends to be more short-lived, and mid-day temperatures are significantly higher than they are on the coast, typically in the low 80s F. This is particularly true for Petaluma, [[Cotati, California|Cotati]], and [[Rohnert Park, California|Rohnert Park]], and, only slightly less so, Santa Rosa, [[Windsor, California|Windsor]], and [[Sebastopol, California|Sebastopol]]. In large part, this results from lower elevations and the prominent [[Petaluma Gap]] in the hills between the ocean to the west and the Petaluma Valley and Santa Rosa Plain to the east.

Areas north of Santa Rosa and Windsor, with larger elevations to the west and further from the fog path, tend to receive less fog and less summer marine influence. Healdsburg, to the north of Windsor, is less foggy and much warmer, with summer highs typically in the higher 80s to about {{convert|90|°F|°C|abbr=on}}. Sonoma and the Sonoma Valley, east of Petaluma, are similar, with highs typically in the very high 70s F to {{convert|80|°F|°C|abbr=on}}. This is in part due to the presence of the Sonoma Mountains between Petaluma and Sonoma. [[Cloverdale, California|Cloverdale]], far to the north and outside of the Santa Rosa Plain, is significantly hotter than any other city in the county, with rare evening-morning fog and highs often in the 90s, reaching {{convert|100|°F|°C|abbr=on}} much more frequently than the other cities. Notably, however, the temperature differences among the different areas of the county are greatest for the highs during mid-day, with the diurnal lows much more even throughout the entire county. The lows are closely tied to the evening-morning cooling marine influence, in addition to elevation, bringing similarly cool temperatures to much of region.

These weather patterns contribute to high diurnal temperature fluctuations in much of the county. In summer, daily lows and highs are typically 30–40&nbsp;°F apart inland, with highs for Petaluma, Cotati, Rohnert Park, Santa Rosa, Windsor, and Sebastopol typically being in the very low 80s F and lows at or near {{convert|50|°F|°C|abbr=on}}. Healdsburg and the City of Sonoma, with similar lows, have even greater diurnal fluctuations due to their significantly warmer highs. On the other hand, the coast, with strong marine influence, tends to have low diurnal temperature fluctuation, with summer highs much cooler than the inland towns, typically 65–75&nbsp;°F, yet lows in the high 40s to low 50s F, fairly comparable to most inland towns.

These microclimates are evident during the rainy seasons as well, with great variation in the amount of rainfall throughout the county. Generally, all of Sonoma County receives a fair amount of rain, with much of the county receiving between about {{convert|25|in|mm|abbr=on}}, comparable to areas such as Sonoma and Petaluma, and roughly {{convert|30|in|mm|abbr=on}} normal for Santa Rosa. However, certain areas, particularly in the north-west portion of the county around the Russian River, receive significantly more rainfall. The [[Guerneville, California|Guerneville]] area, for example, typically receives about {{convert|50|in|mm|abbr=on}} of rain a year, with annual rain occasionally going as high as {{convert|70|in|mm|abbr=on}}. Nearby Cazadero typically receives about {{convert|72|in|mm|abbr=on}} of rain a year, many times has reached over {{convert|100|in|mm|abbr=on}} a year, and sometimes over {{convert|120|in|mm|abbr=on}} of rain in a year. The Cazadero region is the second wettest place in California after [[Gasquet, California|Gasquet]].<ref>{{cite web|url=http://abclocal.go.com/kgo/story?section=local&id=4058640|title=Rainiest Town In The Bay Area Up For Sale|access-date=December 13, 2007|last=Freedman|first=Wayne|date=April 5, 2006|publisher=[[KGO-TV]] News|archive-url=https://web.archive.org/web/20110521143346/http://abclocal.go.com/kgo/story?section=news%2Flocal&id=4058640|archive-date=May 21, 2011|url-status=dead}}</ref>

Snow is exceedingly rare in Sonoma County, except in the higher elevations on and around the [[Mayacamas Mountains]], particularly [[Mount Saint Helena]], and [[Cobb Mountain]], whose peak is in Lake County.<ref>{{cite web |title=Subsection M261Be Konocti Flows |publisher=U.S. Forest Service |url=http://www.fs.fed.us/r5/projects/ecoregions/m261be.htm |archive-url=https://web.archive.org/web/20110922101445/http://www.fs.fed.us/r5/projects/ecoregions/m261be.htm |archive-date=September 22, 2011 |access-date=February 22, 2014}}
</ref>

===Ocean, bays, rivers and streams===
[[File:Sonoma coastline from Bodega Head-L1001155.jpg|thumb|Typical Sonoma County coastline as seen from Bodega Head]]
Sonoma County is bounded on the west by the Pacific Ocean, and has {{convert|76|mi|km}} of coastline. The major coastal hydrographic features are [[Bodega Bay]], the mouth of the Russian River, and the mouth of the [[Gualala River]], at the border with [[Mendocino County]]. All of the county's beaches were listed as among the cleanest in the state in 2010.<ref name="dirty">{{cite news|url=https://www.sfgate.com/bayarea/article/Bay-Area-beaches-grade-well-for-safe-swimming-3187113.php |title=Bay Area beaches grade well for safe swimming |date=May 27, 2010 |author=Carolyn Jones |newspaper=San Francisco Chronicle}}</ref>

Six of the county's nine cities, from Healdsburg south through Santa Rosa to Rohnert Park and Cotati, are in the Santa Rosa Plain. The northern Plain drains directly to the Russian River, or to a tributary; the southern Plain drains to the Russian River via the [[Laguna de Santa Rosa]].

====Russian River====
[[File:Russian River mouth on California coast.jpeg|thumb|[[Goat Rock Beach]] as viewed from the Jenner Cliffs looking south, showing the [[estuary|mouth]] of the [[Russian River (California)|Russian River]] at the Pacific Ocean]]
Much of central and northern Sonoma County is in the watershed of the Russian River and its tributaries. The river rises in the coastal mountains of Mendocino County, north of the city of [[Ukiah, California|Ukiah]], and flows into [[Lake Mendocino]], a major flood control reservoir. The river flows south from the lake through Mendocino to Sonoma County, paralleled by Highway 101. It turns west at Healdsburg, receiving water from [[Lake Sonoma]] via [[Dry Creek (Sonoma County, California)|Dry Creek]], and empties into the Pacific Ocean at [[Jenner, California|Jenner]].

====Laguna de Santa Rosa====
The Laguna de Santa Rosa is the largest tributary of the Russian River.<ref>{{cite web |url=http://www.lagunafoundation.org/about_ecology.htm |archive-url=https://web.archive.org/web/20110722010816/http://www.lagunafoundation.org/about_ecology.htm |url-status=dead |archive-date=July 22, 2011 |title=The Ecology of the Laguna de Santa Rosa |website=lagunafoundation.org |publisher=Laguna de Santa Rosa Foundation |access-date=July 17, 2014 }}</ref> It is {{convert|14|mi|km}} long, running north from Cotati to the Russian River near Forestville. Its flood plain is more than {{convert|7,500|acre|km2}}. It drains a {{convert|254|sqmi|km2|adj=on}} watershed, including most of the Santa Rosa Plain.

The Laguna de Santa Rosa Foundation says:<ref>{{cite web|url=http://www.lagunadesantarosa.org/ecology.html |website=lagunadesantarosa.org |title=Ecology |publisher=Laguna de Santa Rosa Foundation |url-status=dead |archive-url=https://web.archive.org/web/20070206161535/http://www.lagunadesantarosa.org/ecology.html |archive-date=February 6, 2007 }}</ref>

<blockquote>The Laguna de Santa Rosa is Sonoma County's richest area of wildlife habitat, and the most biologically diverse region of Sonoma County (itself the second-most biologically diverse county in California)... It is a unique ecological system covering more than {{convert|30,000|acre|km2}} and {{sic|comprised|hide=y|of}} a mosaic of creeks, open water, perennial marshes, seasonal wetlands, riparian forests, oak woodlands, and grasslands... As the receiving water of a watershed where most of the county's human population lives, it is a landscape feature of critical importance to Sonoma County's water quality, flood control, and biodiversity.</blockquote>

The Laguna's largest tributary is [[Santa Rosa Creek]], which runs through Santa Rosa. Its major tributaries are [[Brush Creek (Sonoma County, California)|Brush Creek]], Mark West Creek, [[Matanzas Creek]], [[Spring Creek (Sonoma County, California)|Spring Creek]], and [[Piner Creek]]. Santa Rosa Creek was shown to be polluted in Sonoma county first flush results.<ref>{{Cite web|url=https://www.govtech.com/em/disaster/Damage-to-Creeks-Water-Supply-Analyzed-After-Sonoma-County-Fires.html|title=Damage to Creeks, Water Supply Analyzed After Sonoma County Fires|date=2017|website=www.govtech.com|language=en|access-date=March 18, 2019}}</ref>

====Other water bodies====
The boundary with [[Marin County, California|Marin County]] runs from the mouth of the [[Estero Americano]] at [[Bodega Bay]], up Americano Creek, then overland to [[San Antonio Creek (Marin County, California)|San Antonio Creek]] and down the Petaluma River to its mouth at the northwest corner of [[San Pablo Bay]], which adjoins [[San Francisco Bay]]. The southern edge of Sonoma County comprises the northern shore of San Pablo Bay between the Marin County border at the Petaluma River and the border with Solano County at [[Sonoma Creek]]. Sonoma County has no incorporated communities directly on the shore of San Pablo Bay.

The Petaluma River, [[Tolay Creek]], and Sonoma Creek enter the bay at the county's southernmost tip. The intertidal zone where they join the bay is the vast [[Napa Sonoma Marsh]].

[[Americano Creek]], the Petaluma River, Tolay Creek, and Sonoma Creek are the principal streams draining the southern portion of the county. The Sonoma Valley is drained by Sonoma Creek, whose major tributaries are [[Yulupa Creek]], [[Graham Creek (Sonoma County, California)|Graham Creek]], [[Calabazas Creek]], Schell Creek, and [[Carriger Creek]]; [[Arroyo Seco Creek]] is a tributary to Schell Creek. Other creeks include Foss, Felta, and Mill.

Lakes and reservoirs in the county include Lake Sonoma, [[Tolay Lake]], [[Lake Ilsanjo]], [[Santa Rosa Creek Reservoir]], [[Lake Ralphine]], and [[Fountaingrove Lake]].

===Marine protected areas===
Like underwater parks, these [[marine protected area]]s help conserve ocean wildlife and marine ecosystems.
*[[Del Mar Landing State Marine Reserve]]
*[[Stewarts Point State Marine Reserve & Stewarts Point State Marine Conservation Area]]
*[[Salt Point State Marine Conservation Area]]
*[[Gerstle Cove State Marine Reserve]]
*[[Russian River State Marine Reserve and Russian River State Marine Conservation Area]]
*[[Bodega Head State Marine Reserve & Bodega Head State Marine Conservation Area]]
*[[Estero Americano State Marine Recreational Management Area]]

===Threatened/endangered species===

A number of endangered plants and animals are found in Sonoma County, including the [[California clapper rail]] (''Rallus longirostris obsoletus''), [[salt marsh harvest mouse]] (''Reithrodontomys raviventris''), [[northern red-legged frog]] (''Rana aurora''), [[Sacramento splittail]] (''Pogonichthys macrolepidotus''), California freshwater shrimp (''[[Syncaris pacifica]]''), showy Indian clover (''[[Trifolium amoenum]]''), Hickman's potentilla (''[[Potentilla hickmanii]]''), ''[[northern spotted owl]]'' (Strix occidentalis caurina), and ''[[marbled murrelet]]'' (Brachyramphus marmoratus).

Species of special local concern include the [[California tiger salamander]] (''Ambystoma californiense''), [[coho salmon]], and some endangered plants, including Burke's goldfields (''[[Lasthenia burkei]]''), Sebastopol meadowfoam (''[[Limnanthes vinculans]]''), and Sonoma sunshine or Baker's stickyseed (''[[Blennosperma bakeri]]'').

Endangered species that are [[endemic (ecology)|endemic]] to Sonoma County include Sebastopol meadowfoam, Sonoma sunshine, and Pitkin Marsh lily ([[Lilium pardalinum subsp. pitkinense|''Lilium pardalinum'' subsp. ''pitkinense'']]).

The [[Sonoma County Water Agency]] has had a Fisheries Enhancement Program since 1996. Its website says:<ref>{{cite web|url=http://www.scwa.ca.gov/environment/natural_resources/fisheries_enhancement.php |publisher=Sonoma County Water Agency |title=Fisheries Enhancement Program |url-status=dead |archive-url=https://web.archive.org/web/20091002073118/http://www.scwa.ca.gov/environment/natural_resources/fisheries_enhancement.php |archive-date=October 2, 2009 }}</ref>

<blockquote>"The primary focus of the FEP is to enhance habitat for three [[salmonid]]s: [[Rainbow trout|Steelhead]], [[Chinook salmon]], and [[Coho salmon]]. These three species are listed as threatened under the U.S. [[Endangered Species Act]]. The California Department of Fish and Game considers the Coho salmon endangered."</blockquote>

===Adjacent counties===
*[[Mendocino County, California]] – north
*[[Lake County, California]] – northeast
*[[Napa County, California]] – east
*[[Solano County, California]] – southeast
*[[Marin County, California]] – south
*[[Contra Costa County, California]] – south-southeast<ref>Marin, Solono, Sonoma and Contra Costa Counties' borders come to a common point approx. 6 miles into San Francisco Bay. Thus, Contra Costa County is an adjacent county.  {{cite book | url=https://archive.org/details/codesandstatute02caligoog | quote=3955. | page=[https://archive.org/details/codesandstatute02caligoog/page/n522 515] | title=The codes and statutes of the State of California | year=1876 | publisher=A. L. Bancroft | last=Hittell | first = Theodore Henry | access-date=August 20, 2012}}</ref><ref>{{cite web | url=http://www.leginfo.ca.gov/cgi-bin/waisgate?WAISdocID=50731529530+1+0+0&WAISaction=retrieve | access-date=August 20, 2012 | title=California Codes, Government Codes, section 23149}}</ref>

===National protected area===
* [[San Pablo Bay National Wildlife Refuge]] (part)