{{Short description|State of California property in Sonoma County}} {{Use mdy dates|date=August 2023}} {{Infobox protected area | name = Sonoma Coast State Park | iucn_category = | image = Archedrocksocounty.jpg | location = [[Sonoma County, California]] | nearest_city = [[Jenner, California|Jenner]] | coordinates = {{coord|38|22|8.39|N|123|4|25.28|W|region:US-CA|format=dms|display=inline,title}} | area = | established = | visitation_num = | visitation_year = | governing_body = [[California Department of Parks and Recreation]] }} [[File:Kortum_Trail_viewed_from_Peaked_Hill.jpg|thumb|right|View southward from Peaked Hill near the north end of the Kortum Trail. Sunset Boulders are visible on the lower left edge of the photo.]] '''Sonoma Coast State Park''' is a State of [[California]] property in [[Sonoma County]] consisting of public access use on lands adjoining the [[Pacific Ocean]]. This extent of beach runs from a coastal point about {{convert|4|mi|km|0}} north of [[Jenner, California|Jenner]] and continues for approximately {{convert|17|mi|km|0}} to the south to terminate at [[Bodega Head]]. The property lies along [[California State Route 1|State Route 1]] and consists of a number of named beaches including Arched Rock Beach, Gleason Beach and [[Goat Rock Beach]]. The ecosystem consists of alternating sandy beaches and [[rocky shore]]line, with a [[marine terrace]] extending above the entire extent with an upland [[California coastal prairie]] habitat.
==Geology== [[File:Sunset Boulders.jpg|thumb|right|Sunset Boulders (also known as Mammoth Rocks) are a popular [[bouldering]] site with evidence of use by ancient [[mammoth]]. A climber atop the rightmost boulder illustrates scale.]] This strip of [[coast]]al property is subject to continuing marine [[erosion]] as well as windborne erosion, thus creating a situation where an average of one to three feet (30 to 90 cm) per year of land mass is lost. Obviously in years of heavy storms this value can be higher, whereas, in a less stormy year the land erosion can be lower. Over the last [[geology|geologic]] epoch the land has been subject to uplift, a process which has created a [[marine terrace]] of the entire extent of the property. This marine terrace is elevated approximately 50 to 100 feet (15 to 30 meters) above [[mean sea level]], which results in a steep [[Cliff|bluff]] directly above the [[littoral]] zone.
Vertical rock formations are a geological hallmark of this site, and have weathered far less than the bulk of the soils. These features are known as [[sea stack]]s, and they appear standing out of the water or on the [[beach]] as though as sculptures placed decoratively along the shoreline. Occasionally these stacks appear as adornments on the marine terrace, indicating their ancient origin on the sea floor prior to uplift. These rock formations are composed of [[sandstone]] with layers of [[quartz]].
[[File:CA 1 north of Jenner.jpg|thumb|right|[[California coastal prairie|Coastal prairie]] in the Sonoma Coast State Park north of [[Jenner, California|Jenner]]]] The active [[San Andreas Fault]] runs roughly parallel and near to the coastline of Sonoma Coast State Park. Soils within the site are classified as coastal beach sands (where rocky shoreline is not evident) and marine [[escarpment]] group soils on the marine terrace; typically soils above the marine terrace are in the Rohnerville loam group.<ref>''Soil Survey, Sonoma County, California'', [[U.S. Department of Agriculture]], [[Soil Conservation Service]], Government Printing Office, Washington DC, May 1972</ref> Most of the beach sands consist of a medium coarse brown to gray sandy materials, reflecting the high rate of erosion of escarpment soils into the ocean. There are patches of smooth pebble beach such as the approximately one hundred meter stretch lying immediately north of Goat Rock.
==Ecology== The habitats include marine, littoral and [[California coastal prairie|coastal prairie]]. In the marine environment are found [[gray whale]]s, [[harbor seal]]s and [[California sea lion]]s as well as a multitude of fish [[species]] and other marine organisms. There are also modest [[kelp bed]]s and other marine vegetation. The littoral beach environment has fewer organisms than more southerly zones, because of the colder temperatures; however, there are [[tidepool]]s which are abundant with marine [[flora]] and [[fauna]].
[[Russian River State Marine Reserve and Russian River State Marine Conservation Area]] and [[Bodega Head State Marine Reserve & Bodega Head State Marine Conservation Area]] protect area resources. Like underwater parks, these marine protected areas help conserve ocean and freshwater wildlife and marine ecosystems.
The coastal prairie soils are moderately well drained and granular in nature with moderate soil permeability; these features lead to slight erosion potential and moderately high bio-productivity. Acidity of these loamy soils is medium to high, and thus some [[pygmy forest|vegetative stunting]] and hospitality to [[rare species|rare plants]] is offered. The upland environment on the coastal prairie offers a variety of [[grass]]es and [[wildflower]]s including varieties of [[Lupinus|lupine]], [[thistle]] and [[wild oat]]s. The typical annual plant productivity is approximately {{convert|3300|lb|abbr=on}} per acre (3700 kg/ha) of air-dried yield per annum in an abundant moisture year, and about half that amount in a very dry year. A variety of birds and mammals thrive on the coastal prairie including numerous [[California Mule Deer]], ''Odocoileus hemionus californicus''. The adjacent [[Ocean Song]] preserve expands the protected area for wildlife and natural vegetation to include ridge-top habitats of the [[California Coast Ranges]].<ref>{{cite web |url=https://www.landpaths.org/ocean-song/ |title=Ocean Song/Myers |publisher=[[LandPaths]] |accessdate=8 October 2023 }}</ref>
==History== [[File:Furlong Gulch.jpg|thumb|right|Furlong Gulch is the deepest gulch crossed by the Kortum Trail and has the easiest beach access along the trail.]] Some of the oldest [[natural history]] of this area related to [[mammal]]s are a [[blueschist]] rock formation about one mile (1.6 km) south of the Russian River. There is found a sea stack formation with prominent rubbing marks about two to four meters in elevation, a height too high to have been caused by modern bovids. [[Mammoth]]s are believed to have roamed here as recently as 40,000 years ago, and they are thought to have created these severe rubbing marks.<ref>E. Breck Parkman, ''Mammoth Rocks: Part 1, Where [[Pleistocene]] Giants got Good Rub'', Center for the Study of the First Americans, Mammoths Series, Volume 18, Number 1, December 2002</ref> Mammoth fossil remains have been found at [[Bodega Head]] at the south end of Sonoma Coast State Park.
Earliest known human settlement of this site was by the [[Coast Miwok]] and [[Pomo]] tribes. As early as 1849 archaeological finds were recorded on this property, and to date dozens of prehistorical kitchen [[midden]]s and other types of tribal habitation finds have been made. The property is part of the [[Ranchos of California|Mexican land grant]] [[Rancho Bodega]]. The [[Russians]] are thought to have begun logging the [[old-growth forest]]s directly above the coastal prairie in the early 19th century.
[[File:DuncansPoint3265.jpg|thumb|right|Duncans Point in 2009]] The underwater delineation of the property is considered to extend to {{convert|1000|ft|m}} from the [[shore]]line. While no [[shipwreck]]s have been discovered, the literature indicates that there are 17 vessels which may have been lost in these waters. There are remains of numerous historic barns and other [[agricultural]] buildings on the coastal prairie indicating 19th century settlement by [[Europe]]ans; at [[Duncans Point]] there are iron pins embedded in the sandstone bluffs as evidence of the active shipping industry here in the late 19th century and early 20th century.
==California Coastal Trail== The park is along the [[California Coastal Trail]]. State route 1 was rerouted due to [[sea level rise]] at Gleason Beach and was repurposed to improve the trail.<ref>{{Cite web |last=Xia |first=Rosanna |date=2025-08-10 |title=Salvaging a crumbling California coastline required some radical thinking |url=https://www.latimes.com/environment/story/2025-08-10/saving-gleason-beach-sea-level-rise |website=Los Angeles Times |language=en-US}}</ref><ref>{{Cite web |last=Fusek |first=Maggie |date=2023-11-22 |title=CA Highway 1 Moved 400 Feet, Marks 1st Sea-Level Rise Caltrans Project |url=https://patch.com/california/petaluma/ca-highway-1-moved-400-feet-marks-1st-sea-level-rise-caltrans-project |access-date=2023-11-23 |website=Petaluma, CA Patch |language=en}}</ref>
===Kortum Trail=== [[File:Kortum_Trail_Wooden_Walkway.jpg|thumb|right|Kortum Trail includes this wooden walkway over wetlands within California's Sonoma Coast State Park.]] {{routemap |title=Kortum Trail |map= WFILL\fSTR+l\RP2q~~Goat Rock Road WFILL\fGDTgg\ WFILL\fOBJrl\~~Sunset Boulders WFILL\fSTR\ WFILL\fGDTg\ WFILL\fhKRZWae\LWSTRq~~ WFILL\fGDTf\ WFILL\fhSTRa@g\ WFILL\fhSTRe@f\ WFILL\fSTR\ WFILL\fhKRZWa\LWSTRq~~ WFILL\fhSTRe@f\ WFILL\fSTR\ WFILL\fhSTRa@g\ WFILL\fhSTRe@f\ WFILL\fOBJr\~~Labyrinth WFILL\fABZgl\RP2q~~Pacific View Drive WFILL\fABZl+l\RP2q~~Shell Beach WFILL\fhKRZWae\LWSTRq~~ WFILL\fSTR\ WFILL\fhKRZWae\LWSTRq WFILL\fGDTg\ WFILL\fhKRZWae\LWSTRq~~Furlong Gulch WFILL\fGDTf\ WFILL\fABZl+l\RP2q~~Carlevaro Way WFILL\fhKRZWae\LWSTRq~~ WFILL\fhKRZWae\LWSTRq~~ WFILL\fhSTRa@g\ WFILL\fhSTRe@f\ WFILL\fSTR\ WFILL\fSTRl\RP2q~~Wrights Beach }} Although some parts of the park are too steep for easy access between Route 1 and the ocean, Kortum Trail is convenient for hiking between highway access points at Goat Rock, Shell Beach, and Wright's Beach.<ref>{{cite web |url=https://www.sonomacounty.com/outdoor-activities/kortum-trail |title=Kortum Trail |website=SonomaCounty.com |access-date=11 November 2020 }}</ref> Total trail length is approximately {{cvt|3.8|mi|km}}.<ref>{{cite web |url=https://www.outdoorproject.com/united-states/california/kortum-trail |title=Kortum Trail |last=Bosworth |first=Aron |website=OutdoorProject.com |access-date=11 November 2020 }}</ref> The well-maintained trail includes wooden walkways across wetlands and bridges over streams.<ref>{{cite web |url=https://www.alltrails.com/trail/us/california/kortum-trail--2 |title=Kortum Trail |publisher=[[AllTrails]] |access-date=11 November 2020 }}</ref> Side trails offer access to the beach and to [[bouldering]] opportunities at Sunset Boulders. Whales may be seen offshore and wildflowers, birds, and deer can be observed within the coastal park.<ref>{{cite web |url=https://www.sonomanews.com/article/lifestyle/five-hidden-secrets-on-sonoma-coasts-kortum-trail/?sba=AAS |title=Five hidden secrets on Sonoma Coast's Kortum Trail |last=Nett |first=Stephen |publisher=[[Sonoma Index-Tribune]] |access-date=11 November 2020 }}</ref>
The trail was named for Sonoma County environmentalist Bill Kortum (1927–2014). Bill's mother was a descendant of the [[Donner Party]] and his father's parents were early [[California wine]]makers in the upper [[Napa Valley AVA|Napa Valley]]. After spending his youth on a [[Petaluma, California|Petaluma]] poultry and dairy farm, Bill studied [[veterinary medicine]] at [[Santa Rosa Junior College]] and the [[University of California, Davis]]. His travels as a [[bovine]] veterinarian gave him an appreciation for California's disappearing rural landscape, and encouraged his environmental activism for formation of the [[California Coastal Commission]].<ref>{{cite web |url=https://www.conservationaction.org/bill-kortum/ |title=Bill Kortum |publisher=Sonoma County Conservation Action |access-date=11 November 2020 }}</ref>
==See also== * [[Jenner Headlands Preserve]] * [[Doran Regional Park]] * [[Estero Americano Coast Preserve]] * [[Salmon Creek, California]] * [[Sonoma Coast State Marine Conservation Area]] * [[List of beaches in Sonoma County, California]] * [[List of California state parks]] * [[List of Sonoma County Regional Parks facilities]]
== References== {{reflist}}
==External links== * [http://www.parks.ca.gov/?page_id=451 California State Parks official site for Sonoma Coast State Park] * [http://www.sonoma-county.org/points/state_parks_sonoma_coast.htm Sonoma Coast State Park - Sonoma County Points of Interest]
{{Protected areas of California|SP}} {{California hiking trails}}
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[[Category:State parks of California]] [[Category:Parks in Sonoma County, California]] [[Category:San Francisco Bay Area beaches]] [[Category:Beaches of Sonoma County, California]] [[Category:Beaches of Northern California]]