The Potrero Hills also known as the Potrero Ridge and Point Molate Hills is a

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranea ...

and forested

escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...

that crests northwest to southeast along the San Pablo Peninsula in

Richmond, California Richmond is a city in western Contra Costa County, California, United States. The city was incorporated on August 7, 1905, and has a city council.

.Point Molate Casino EIR, Volume I, 2009, accessed May 25, 2010
/ref>Point Molate Resort and Casino
city of Richmond website, May 25, 2010

History

The steep hills crest from

Point Richmond Point Richmond, also sometimes referred to locally as The Point, is a neighborhood in Richmond, California, Richmond, California, United States, near the eastern end of the Richmond-San Rafael Bridge, between Interstate 580 (California), Inters ...

in the south to Point San Pablo in the north. They were formed by pressure created by the San Pablo Fault a sub-fault of the

Hayward Fault The Hayward Fault Zone is a right-lateral strike-slip geologic fault zone capable of generating destructive earthquakes. This fault is about long, situated mainly along the western base of the hills on the east side of San Francisco Bay. It run ...

. Part of the hills once were cultivated as a vineyard for the Winehaven Winery, world's largest winery at the time. The range hosts two peaks the largest is a 494-feet (151 m) and the second largest a 328 feet (100 m) peak, both are unnamed. The hills once formed the backbone of an island the existed off the coast of what is now central Richmond and has been landfilled, similar to

Alameda An alameda is a street or path lined with trees () and may refer to: Places Canada * Alameda, Saskatchewan, town in Saskatchewan ** Grant Devine Dam, formerly ''Alameda Dam'', a dam and reservoir in southern Saskatchewan Chile * Alameda (Santia ...

Bay Farm Island Bay Farm Island is a district of the city of Alameda, California, though it is separated from the rest of the city on Alameda Island by an estuary of San Leandro Bay. Its ZIP code is 94502. The location was originally an island in San Francisco B ...

. The hills are made of

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

, and

chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a ...

Industry

The hills provide a natural barrier protecting the Point Molate area from

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...

and other contaminants that could be released from the

Chevron Richmond Refinery The Chevron Richmond Refinery is a petroleum refinery in Richmond, California, on San Francisco Bay.

in the event of a disaster. A pass is carved into it at its southern end for Interstate 580. Some of the ridge was also formerly used for goat grazing and quarrying at the Blake Brothers Quarry. A weather station sits atop a peak overlooking Point San Pablo.

Point Potrero Pond Potrero Hills Pond is a small lake in Richmond, California. It was formed from quarrying of hills near Potrero Hills at the Blake Brothers Quarry.

is a small lake near the

Richmond–San Rafael Bridge The Richmond–San Rafael Bridge (also officially named the John F. McCarthy Memorial Bridge) is the northernmost of the east–west crossings of the San Francisco Bay in California, USA. Officially named after California State Senator John F ...

toll plaza near the south of the hills. The hills are dotted with tank farms and polluted sites from the former

Point Molate Naval Fuel Depot Point Molate Naval Fuel Depot is a decommissioned United States Navy fueling station on the western shore of Richmond, California on San Francisco Bay. It has undergone years of litigation and debate as to its redevelopment with proposals ranging ...

.Changes in the Richmond Waterfront
access date 25-02-2009 The hills vegetation is largely composed of

eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as ...

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the '' plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...

s with some

wetlands A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The p ...

as well.

Notes

External links

Aerial view of the hills
{{East Bay Mountain ranges of Contra Costa County, California Geography of Richmond, California Hills of California San Pablo Bay Mountain ranges of the San Francisco Bay Area