Richardson Bay

Last updated
Richardson Bay
Richardson Bay 4.jpg
Richardson Bay viewed from Mount Tamalpais
Location Map San Francisco Bay Area.png
Red pog.svg
Richardson Bay
Location of Richardson Bay across from San Francisco
Location San Francisco Bay
Coordinates 37°52′30″N122°29′00″W / 37.87500°N 122.48333°W / 37.87500; -122.48333 Coordinates: 37°52′30″N122°29′00″W / 37.87500°N 122.48333°W / 37.87500; -122.48333
Type Bay
Etymology William A. Richardson
Primary inflows Arroyo Corte Madera del Presidio, Coyote Creek
Average depth20 ft (6.1 m)

Richardson Bay (originally Richardson's Bay) is a shallow, ecologically rich arm of San Francisco Bay, managed under a Joint Powers Agency of four northern California cities. [1] The 911-acre (369 ha) Richardson Bay Sanctuary was acquired in the early 1960s by the National Audubon Society. [2] The bay was named for William A. Richardson, early 19th century sea captain and builder in San Francisco. It contains both Strawberry Spit and Aramburu Island.


In spite of its urbanized periphery, Richardson Bay supports extensive eelgrass areas and sizable undisturbed intertidal habitats. It is a feeding and resting area for a panoply of estuarine and pelagic birds, while its associated marshes and littoral zones support a variety of animal and plant life. Richardson Bay has been designated as an Important Bird Area (IBA), based upon its large number of annual bird visitors and residents, its sightings of California clapper rail and its strategic location on the Pacific Flyway. The bay's waters are subject to a "no discharge" rule to protect the elaborate and fragile ecosystems present, including a complex fishery, diverse mollusk populations and even marine mammals such as the harbor seal.

Owing to its lack of depth and complicated channel structure, Richardson Bay is limited in boating uses to kayaking and small sailing craft. There are extensive hiking and bicycling paths at the bay perimeter, especially in the shore areas of Mill Valley and the town of Tiburon. [3]

History of the name

William Richardson William Richardson.jpg
William Richardson

On August 22, 1822, an English whaler, the Orion, put into Yerba Buena Cove in San Francisco for supplies; the captain was William Anthony Richardson, described as tall, fair haired, blue-eyed and young, was sighted by Maria Antonia, daughter of the Commandante of the Presidio of San Francisco, Ygnacio Martinez. Martinez, for whom the town of Martinez is named, decided to invite the Captain to reside with their family. Maria married the captain after he joined the Catholic Church, being baptized "Guillermo Antonio Richardson." This wedding, held at Mission Dolores on May 12, 1826 was the first great Spanish-Anglo Saxon wedding in North America. [4] [5]

Richardson taught carpentry, boat building and navigation at Mission Dolores, served as Captain of the Port of San Francisco, and built the first significant residence in San Francisco, although it was meant to be a trading post. He had charge of several schooners belonging to the Mission Dolores and Mission Santa Clara. Richardson received a 19,500-acre (79 km2) Mexican land grant in 1838, Rancho Saucelito, which is all of the land north of the Golden Gate extending from bay to ocean and ranging north to Mount Tamalpais The grant contained all the land southeast of Mount Tamalpais, and included Redwood Canyon and the lands now within Muir Woods National Monument. Richardson Bay was thus named in the honor of this energetic early settler and builder.

The Tiburon Peninsula on the northeast side of the bay was part of Rancho Corte Madera del Presidio granted to John Thomas Reed in 1834.

According to local sources [6] [7] and period maps, [8] the Bay's original given name was possessive: Richardson's Bay. However, the United States Board on Geographic Names discourages the use of apostrophes in United States place names, [9] which is why the name appears as Richardson Bay in government databases [10] and maps. [11]


Richardson Bay is developed on surficial sediments of clays, silts and minor sands and gravels deposited in a primarily marine and estuarine environment during periods of previous high stands of water relative to the present shoreline. The bay muds are widespread in San Francisco Bay and, at Richardson Bay, are approximately 80 to 95 feet (24 to 30 meters) deep . [12] The Bay Muds are of Holocene Age (less than 10,000 years of age). They overlie firm alluvial soils which contain two sand layers at 92 and 110 feet (29 and 35 meters), respectively. This section, in turn, overlies shale of the Franciscan Complex, a heterogeneous mixture of sedimentary, igneous and metamorphic rock gathered together in the course of the tectonic evolution of the region from the Late Jurassic to the Middle Miocene. These assemblages of Franciscan rocks are referred to as tectonostratigraphic terrains and two of them, the Central Belt and the Coastal Belt, are in fault contact near Richardson Bay.


Black-necked stilt foraging in Richardson Bay mudflat Bnstiltpair.jpg
Black-necked stilt foraging in Richardson Bay mudflat
The outlet of Coyote Creek, which drains Tam Valley into upper Richardson's Bay Pickleweedecreekerazorback.jpg
The outlet of Coyote Creek, which drains Tam Valley into upper Richardson's Bay

Richardson Bay is an important ecological area being managed by Audubon California as the Richardson Bay Audubon Center & Sanctuary. [2] There are significant estuarine resources, marsh birdlife, mammalian species and marsh plants. [13]

Birds are abundant in Richardson Bay, with over one million migratory visitors each winter, many of whom utilizing the upper mudflats and Bothin Marsh associated with the area west of the U.S. Route 101. In addition to being designated a high score IBA, Richardson's Bay has been dedicated as a Hemispheric Reserve of the Western Shorebird Network. Migrating birds that winter regularly at Richardson's Bay include least sandpiper, western sandpiper, spotted sandpiper, American avocet, dunlin, marbled godwit, greater yellowlegs, willet, long-billed curlew and dowitchers . A special resident of Bothin Marsh, Blackies' Creek mouth and DeSilva Island is the California clapper rail, a non-migratory endangered species. [2] Beginning in 2014, endangered black oystercatchers have been observed nesting on Aramburu Island. [14]

Common year around residents of the Richardson Bay Sanctuary include great blue heron, snowy egret, and great egret; mallard; red-tailed hawk and turkey vulture; killdeer and western gull; mourning dove and rock dove; Anna's hummingbird. Common residents Passeriformes include scrub jay, American crow, chestnut-backed chickadee, bushtit, Bewick's wren, house sparrow, red-winged blackbird, house finch, California towhee and song sparrow. [15]

Fishery characteristics of Richardson Bay include a Pacific herring fishery and oyster beds. The herring fishing fleet serving all of San Francisco Bay is based in Richardson Bay at the Sausalito harbor. This herring fishing is overseen by the California Department of Fish and Game; the herring population is in a downward trend, although not from excessive fishing pressure with the net techniques in use, but rather from ocean environmental factors. Herring spend most of their lives in the open ocean and come to Richardson Bay and other estuaries for winter spawning in the shallow protected waters. In Richardson Bay their eggs attach to assorted surfaces such as eelgrass, [16] piers or rip rap. After the eggs hatch, the herring larvae consume plankton; before hatching the eggs are subject to predation by gulls at low tide and sturgeon and other assorted estuarine fauna at higher tides.

Regarding the oyster beds, an experimental program is underway as of 2006, in which foreign oyster shells (biologically inert) are bagged and em-placed in underwater locations to serve as larval substrates, in order to assist the native oysters in propagating. Locally oysters are preyed upon by the bat ray and certain crabs.

The extensive mudflats of Richardson Bay provide a rich habitat for marine invertebrates. Many of the species are found elsewhere in San Francisco Bay. Characteristic organisms include burrowing clams, polychaete worms, decapod crustaceans, amphipods, phoronids and anemones. A field survey conducted on a broad mudflat along the Strawberry/Belvedere shoreline found species associated with rocks including: bivalves, ( Macoma balthica , Mya arenaria and Mytilus edulis ); the sea snail Littorina planaxis; the crab Hemigrapsis oregonensis ; the isopod Sphaeroma quoyanum ; the barnacles Balanus glandula and Balanus amphitrite ; the nemertean Lineus ruber ; and the anemones Diadumene leucolena and Haliplanella luciae .

Mammals visiting Richardson Bay include the harbor seal, which hauls out on DeSilva Island and on the Tiburon shore near the Richardson Bay Audubon Sanctuary headquarters. The endangered salt marsh harvest mouse is also thought to be present.

Flora include intertidal and upland species. Probably the most notable feature is the extensive eelgrass population at the tideland perimeter of Richardson Bay. This eelgrass occurrence in Richardson Bay is considered one of the most sizeable stands in Northern California, and it is being restored, leading to further extent of this habitat. There is an extensive pickleweed habitat at the western end of the bay, where many acres of mudflat areas are exposed to shorebirds at low tide at the efflux of Pickleweed Inlet. Upland plants found at the perimeter of Richardson's Bay include toyon, coast live oak, California bay, and native California bunch grasses.

On November 7, 2007, there was a large oil spill in the San Francisco Bay . [17] This Cosco Busan oil spill was found to be lethal to herring fry in oiled versus non-oiled sites in Richardson Bay. [18] This spill has greatly affected the organisms in the bay.

Modern history

Lyford House built 1876 Lyforderazorback.jpg
Lyford House built 1876
An aerial photograph of Richardson Bay, taken from the west, in September 2019 Aerial view of Richardson Bay, September 2019.JPG
An aerial photograph of Richardson Bay, taken from the west, in September 2019

Through the latter 19th century and early 20th century, the land fronting on Richardson Bay was extensively subdivided into public and private ownership encompassing thousands of parcels. The cities of Tiburon, Mill Valley, Belvedere and Sausalito have enacted strong shoreline development policies to protect the perimeter of Richardson Bay, even though considerable development has occurred. The Audubon Society manages the whole Richardson Bay Sanctuary subject to governance by the Joint Powers Agency of the four peripheral cities.

One parcel deeded from Reed to Rosie Verall, who worked for the Reed family, is now the core of the Audubon Richardson Bay Sanctuary. Verall donated this land of approximately 13 acres (5.3 ha) to be held in permanent trust as a wildlife sanctuary. The Audubon Society purchased this upland parcel along with the entirety of the subtidal and intertidal lands of Richardson Bay in 1960. The Lyford House built in 1876 occupies the Verall parcel, even though the house was built at a different location in the vicinity known as Strawberry Point. The house is furnished in period style and is used by the National Audubon Society for special functions and events.

As of 2019, the bay contains about one hundred people who live on boats one-quarter mile from the shore. [19]

Hydrology and boating data

Tiburon harbor looking toward San Francisco Tibboatsrazorback.jpg
Tiburon harbor looking toward San Francisco

Richardson bay joins San Francisco Bay where the water depth becomes 20 feet (6 m), demarcated by a highly irregular boundary connecting the southern end of the Sausalito Marina] with the southern tip of Belvedere, sometimes called Peninsula Point. At this line of demarcation the depth increases rapidly on the San Francisco Bay side, becoming 100 feet (30 m) in depth almost immediately. This portion of San Francisco Bay, also known as Raccoon Strait, possesses highly turbulent waters. Boating in Richardson Bay is limited to small sailing craft and kayaks due to limited draft available, and nearly 900 acres of the bay is closed for six months during the winter each year to provide protection for the ecological system, particularly migratory waterbirds.

Richardson Bay receives inflow from numerous seasonal small unnamed streams and three major streams: Arroyo Corte Madera del Presidio which receives the surface runoff from the steep southeast slopes of Mount Tamalpais; Pickleweed Inlet; and Coyote Creek (Marin County), which receives the runoff from the slopes to the west of Richardson Bay. These streams empty into Richardson Bay from the northwest. Arroyo Corte Madera del Presidio and Coyote Creek are intermittent in flow. [20]

Richardson Bay Audubon Center & Sanctuary

The National Audubon Society operates a nature center in Tiburon that offers adult and children's nature programs, including summer camp, school science programs, birthday and family events, lectures, guided walks, environmental education workshops, Bay Shore Studies docent programs and volunteer projects. Recent efforts included renovation of the human-made islands Aramburu, [21] Pickleweed, and Unnamed [14] to enhance their value as bird refuges.

See also

Related Research Articles

<span class="mw-page-title-main">Mill Valley, California</span> City in California, United States

Mill Valley is a city in Marin County, California, United States, located about 14 miles (23 km) north of San Francisco via the Golden Gate Bridge and 52 miles (84 km) from Napa Valley. The population was 14,231 at the 2020 census.

<span class="mw-page-title-main">Tiburon, California</span> City in California, United States

Tiburon is an incorporated town in Marin County, California. It is located on the Tiburon Peninsula, which reaches south into the San Francisco Bay. It shares a ZIP code with the smaller incorporated city of Belvedere, which occupies the southwest part of the peninsula and is contiguous with Tiburon. Tiburon is bordered by Corte Madera to the north and Mill Valley to the west, but is otherwise mostly surrounded by the bay. Besides Belvedere and Tiburon, much of the peninsula is unincorporated, including portions of the north side and the communities of Strawberry and Paradise Cay.

<span class="mw-page-title-main">Coos Bay</span>

Coos Bay is an estuary where the Coos River enters the Pacific Ocean, the estuary is approximately 12 miles long and up to two miles wide. It is the largest estuary completely within Oregon state lines. The Coos Bay watershed covers an area of about 600 square miles and is located in northern Coos County, Oregon in the United States. The Coos River, which begins in the Oregon Coast Range, enters the bay from the east. From Coos River, the bay forms a sharp loop northward before arching back to the south and out to the Pacific Ocean. Haynes Inlet enters the top of this loop. South Slough branches off from the bay directly before its entrance into the Pacific Ocean. The bay was formed when sea levels rose over 20,000 years ago at the end of the Last Glacial Maximum, flooding the mouth of the Coos River. Coos Bay is Oregon's most important coastal industrial center and international shipping port, with close ties to San Francisco, the Columbia River, Puget Sound and other major ports of the Pacific rim.

<span class="mw-page-title-main">William Anthony Richardson</span> California pioneer, city founder

William Anthony Richardson was an early California entrepreneur, influential in the development of Yerba Buena, the forerunner of the city of San Francisco.

<span class="mw-page-title-main">Ridgway's rail</span> Species of bird

Ridgway's rail is a near-threatened species of bird. It is found principally along the Pacific Coast of North America from the San Francisco Bay Area to southern Baja California, as well as in some regions of the Gulf of California. A member of the rail family, Rallidae, it is a chicken-sized bird that rarely flies. Its common name and Latin binomial commemorate American ornithologist Robert Ridgway.

<span class="mw-page-title-main">Tamalpais Union High School District</span> School district in California

The Tamalpais Union High School District or TUHSD provides high school education to students residing in ten elementary districts in central and southern Marin County, California and parts of West Marin. The headquarters are on the property of Redwood High School in Larkspur, California.

<span class="mw-page-title-main">Arroyo Corte Madera del Presidio</span> River in California, United States

Arroyo Corte Madera del Presidio is a 4.1-mile-long (6.6 km) year-round stream in southern Marin County, California, United States. This watercourse is also known as Corte Madera Creek, although the actual stream of that name flows into San Francisco Bay further north at Point San Quentin. This watercourse has a catchment basin of about 8 square miles (21 km2) and drains the south-eastern slopes of Mount Tamalpais and much of the area in and around the town of Mill Valley; this stream discharges to Richardson Bay.

<span class="mw-page-title-main">Seal Slough</span> Body of water

Seal Slough, also known as Marina Lagoon, is a narrow winding tidal channel through a tidal marsh in San Mateo and Foster City, California. This slough has been the object of a wetland restoration project in recent years to enhance habitat value. Dredging has been carried out in Seal Slough since at least 1954. When the original sewage treatment plant for the city of San Mateo was constructed in 1935, its discharge was directed to Seal Slough.

Bothin Marsh is a 106 acres (43 ha) wetland in Marin County, California. Parts of the wetlands are in the Bothin Marsh Open Space Preserve, a regional park.

<span class="mw-page-title-main">Benjamin and Hilarita Lyford House</span> Historic house in California, United States

The Lyford House is a Victorian house located in Tiburon, California. Built in 1876, the house is listed on the National Register of Historic Places.

Tamalpais Valley is an unincorporated community in Marin County, California.

Rancho Saucelito was a 19,752-acre (79.93 km2) Mexican land grant in present-day Marin County, California, given in 1838 by Governor Juan Alvarado to William A. Richardson. The name means "ranch of the little willow grove". The grant extended from the Pacific Ocean on the west, to Mount Tamalpais to the north, and the Arroyo Corte Madera del Presidio and Richardson Bay on the east; and included present-day Muir Beach, Stinson Beach, Sausalito, Tamalpais Valley, and Homestead Valley.

<span class="mw-page-title-main">Coyote Creek (Marin County)</span> River in California, United States

Coyote Creek is a stream in the Richardson Bay watershed, draining Tamalpais-Homestead Valley, California eastward into Richardson Bay, Marin County, California, United States. The stream originates on Coyote Ridge and flows 2.5 miles (4.0 km) to the bay at the south end of Bothin Marsh.

<span class="mw-page-title-main">Corte Madera Creek (Marin County)</span> River in California, United States

Corte Madera Creek is a short stream which flows southeast for 4.5 miles (7.2 km) in Marin County, California. Corte Madera Creek is formed by the confluence of San Anselmo Creek and Ross Creek in Ross and entering a tidal marsh at Kentfield before connecting to San Francisco Bay near Corte Madera.

<span class="mw-page-title-main">Larkspur Creek</span> River in California, United States

Larkspur Creek is a short stream which flows 3.5 miles east to meet Corte Madera Creek in Larkspur, California just before reaching Richardson's Bay. The creek was named for the town of Larkspur, which was named by Georgiana Wright, a Briton and spouse of the 1887 developer of the area. She named the town of Larkspur for lupine flowers on the hills that she mistook for larkspur.

<span class="mw-page-title-main">Belmont Slough</span> River in California, United States

Belmont Slough is a slough on the western shore of San Francisco Bay separating Redwood Shores and Foster City. It provides estuarine and marine deepwater habitats in its subtidal waters, which are characterized as brackish and saltwater.

The Kendall-Frost Mission Bay Marsh Reserve is a 20-acre University of California Natural Reserve System reserve on the northern shore of Mission Bay in San Diego County, California. Administered by UC San Diego, the site is owned by the University of California and managed for teaching and research.

<span class="mw-page-title-main">Aramburu Island</span> Island in California

Aramburu Island is a 17-acre (6.9 ha) island in Richardson Bay, Marin County, California. It, along with Strawberry Spit, came to exist in the 1950s and 1960s as a consequence of dumping dredged material from nearby developments into the bay. In the 1980s, the northern part of the landmass was cut off from Strawberry Spit on the directions of a Marin County supervisor to prevent housing from being constructed there, creating Aramburu Island. While natural erosion processes caused it to shrink slowly over the course of subsequent decades, a 2010s restoration effort added large amounts of material to prevent further erosion, and turned it into "sustainable bird habitat".

<span class="mw-page-title-main">Richardson Island</span> Former island in California

Richardson Island is a former island in San Francisco Bay, in northern California. While it was once surrounded by water and marsh, development of surrounding areas caused it to become completely surrounded by land by the mid-20th century. It is located in Marin County, in the city of Corte Madera. The United States Geological Survey (USGS) gave its elevation as 16 ft (4.9 m) in 1981. It is near the end of Corte Madera Creek, where it flows into San Francisco Bay.

<span class="mw-page-title-main">Old Mill Creek (Arroyo Corte Madera del Presidio)</span> River in California, United States

Old Mill Creek is a 2.3-mile-long (3.7 km) year-round stream in southern Marin County, California, United States. Old Mill Creek is a tributary to Arroyo Corte Madera del Presidio, which, in turn, flows to Richardson Bay at Mill Valley's municipal Bayfront Park and 106 acres (0.43 km2) Bothin Marsh.


  1. E. Clement Chute Jr; Ailetta d'A. Belin (September 1983). Regulations Report for Richardson Bay Special Area Plan (Report). San Francisco Bay Conservation and Development Commission.
  2. 1 2 3 "Richard Bay Audubon Sanctuary & Ecology Center". Audubon Society. Archived from the original on 2007-11-16. Retrieved 2010-09-05.
  3. Harris and Associates (1977-02-01). Richardson Bay Area Transportation Study (Report). Marin County.
  4. Robert Ryal Miller (1995). Captain Richardson, Mariner, Ranchero, and Founder of San Francisco. Berkeley, California: La Loma Press.
  5. "Captain William Richardson". The Maritime Heritage Project. Retrieved 2010-09-05.
  6. "A Safe Anchorage". Richardson's Bay Maritime Association. Retrieved 2010-09-05.
  7. Phil Frank (October 2008). House Boats of Sausalito, California. p. 128. ISBN   978-0-7385-5552-2.
  8. "David Rumsey Historical Map Collection: Map of the region about San Francisco Bay showing the relation of the city of San Francisco to the San Andreas Rift, the fault of April 18, 1906 and the fault of October 21, 1868". New York: Julius Bien & Co. 1908. Retrieved 2010-09-05.
  9. "BGN: Domestic Names FAQs" . Retrieved 2008-08-13.
  10. U.S. Geological Survey Geographic Names Information System: Richardson Bay
  11. "ACME Mapper" . Retrieved 2008-08-13.
  12. Report, (1981) Harding Lawson Associates (HLA).
  13. Arthur Clayton Smith (1974). Introduction to the natural history of the San Francisco bay region. University of California Press. p. 72. ISBN   978-0-520-01185-4 . Retrieved 2010-09-05.
  14. 1 2 "News and talk tops in overall local radio market". 10 March 2006.
  15. Courtney Buechart; Todd Olson; Margaret Schaeffer; et al. (1996). Checklist of birds of the Richardson Bay Audubon Center and Sanctuary (Report). National Audubon Society (.
  16. Richardson Bay Special Area Plan (PDF) (Report). San Francisco Bay Conservation and Development Commission. April 1984. p. 78. Retrieved 2010-09-05.
  17. Jane Kay (2007-11-11). "Bay cleanup efforts expanding" . Retrieved 2010-09-05.
  18. J.P. Incardona; C.A. Vines (2009). Cosco Busan Oil Spill Natural Resource Damage Assessment. Data Report of Laboratory and Field Herring Injury Studies Performed 2008-2009 (PDF) (Report). California Department of Fish and Game. Retrieved 2010-09-05.
  19. Kloc, Joe. "Lost at Sea: Poverty and paradise at the edge of America". Harper's Magazine . No. May 2019. Retrieved 12 July 2019.
  20. C.Michael Hogan; Gary Deghi; et al. (1990). Environmental Impact Report for the Whalers Point Hotel Project on Richardson's Bay (Report). Earth Metrics Inc, Report 7980, Cal. St. Clearinghouse, County of Marin, California.
  21. "Aramburu Island". Richardson Bay Audubon Center. 22 January 2016.