The Foothills of the San Gabriel Valley are the

foothills Foothills or piedmont are geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an upland area. They are a transition zone between plains and low relief hills and the adjacent topograp ...

and

hill A hill is a landform that extends above the surrounding terrain. It often has a distinct Summit (topography), summit. Terminology The distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally con ...

s in the

San Gabriel Valley The San Gabriel Valley ( es, Valle de San Gabriel) is one of the principal valleys of Southern California, lying immediately to the east of the eastern city limits of the city of Los Angeles, and occupying the vast majority of the eastern part ...

of eastern

Los Angeles County Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the most populous county in the United States and in the U.S. state of California, with 9,861,224 residents estimated as of 2022. It is the ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. They include the foothills of the

San Gabriel Mountains The San Gabriel Mountains ( es, Sierra de San Gabriel) are a mountain range located in northern Los Angeles County, California, Los Angeles County and western San Bernardino County, California, United States. The mountain range is part of the Tr ...

, and independent low

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...

s of hills, in the east

Greater Los Angeles Greater Los Angeles is the second-largest metropolitan region in the United States with a population of 18.5 million in 2021, encompassing five counties in Southern California extending from Ventura County in the west to San Bernardino Coun ...

region. The landforms are part of the

Transverse Ranges The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie within Santa B ...

System of

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...

and

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Geography

The ranges are roughly parallel the

San Andreas fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonics, tectonic boundary between the Pacific Plate and the North American Plate, and its motion is Fault (geology)#Strike-slip fau ...

to the north over the San Gabriel Mountains' ridgeline. They are generally along the Interstate 210 freeway, giving it the name "Foothill Freeway". The Interstate 210 and State Route 210 freeway covers 86 miles, between

Sylmar Sylmar is a suburban neighborhood in the San Fernando Valley and is the northernmost neighborhood within the City of Los Angeles. Historically known for its profusion of sylvan olive orchards, Sylmar can trace its past to the 18th century and th ...

in the west, through the foothills and San Gabriel and

Pomona Valley The Pomona Valley is located in the Greater Los Angeles Area between the San Gabriel Valley and San Bernardino Valley in Southern California. The valley is approximately east of downtown Los Angeles. History On March 1, 1893 the California A ...

s, to Redlands in the east.

Foothills and hill ranges

;The Foothills and Hills in the San Gabriel Valley region include: * Foothills of the

– ''along southern face''. *

Puente Hills The Puente Hills are a chain of hills, one of the lower Transverse Ranges, in an unincorporated area in eastern Los Angeles County, California, in the United States. The western end of the range is often referred to locally as the Whittier Hills. ...

San Jose Hills The San Jose Hills are a part of the Transverse Ranges in eastern Los Angeles County, California, marking the border between the San Gabriel Valley and the Pomona Valley. It includes portions of Covina, West Covina, Walnut, Pomona, and San Dim ...

San Rafael Hills The San Rafael Hills are a mountain range in Los Angeles County, California. They are one of the lower Transverse Ranges, and are parallel to and below the San Gabriel Mountains, adjacent to the San Gabriel Valley overlooking the Los Angeles Bas ...

* South Hills *

Verdugo Mountains The Verdugo Mountains, also known as the Verdugo Hills or simply The Verdugos, are a small, rugged mountain range of the Transverse Ranges system in Los Angeles County, California. Located just south of the western San Gabriel Mountains, the Ver ...

Natural environments

The foothills provide

greenbelt A green belt is a policy and land-use zone designation used in land-use planning to retain areas of largely undeveloped, wild, or agricultural land surrounding or neighboring urban areas. Similar concepts are greenways or green wedges, which h ...

s and contain Open Space Preserves and

Regional park A regional park is an area of land preserved on account of its natural beauty, historic interest, recreational use or other reason, and under the administration of a form of local government. Definition A regional park can be a special park distri ...

s. The undeveloped hill areas are part of California's chaparral and woodlands

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

– with montane chaparral and woodlands and

Oak savanna An oak savanna is a type of savanna—or lightly forested grassland—where oaks (''Quercus ''spp.) are the dominant trees. The terms "oakery" or "woodlands" are also used commonly, though the former is more prevalent when referencing the Mediter ...

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s. Their

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 Mediterranean c ...

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 natur ...

, and

oak woodland An oak woodland is a plant community with a tree canopy dominated by oaks (''Quercus spp.''). In terms of canopy closure, oak woodlands are intermediate between oak savanna, which is more open, and oak forest, which is more closed. Although the ...

plant communities A plant community is a collection or association of plant species within a designated geographical unit, which forms a relatively uniform patch, distinguishable from neighboring patches of different vegetation types. The components of each plant ...

evolved with

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...

s, with some species of their

native plants In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...

dependent on natural fires to regenerate and thrive. Chaparral is California’s most extensive native plant community. It is also one of the State’s most characteristic wilderness types, dominating foothills and mountain slopes. Properly defined, chaparral is a kind of shrub-dominated community of hard-leaved plants shaped by summer drought, mild, wet winters, and fires that naturally occur every 30 to 150 years plus – more frequent fires can lead to habitat loss and conversion to non-native grasslands."Climate, Fire, and Habitat in Southern California." http://ucanr.edu. N.p., n.d. Web. 6 Dec. 2012. Montane forests are generally pine and fir dominated communities that occur at higher elevations in southern California’s mountain areas from 3000 up to 8500 ft. At the lower parts of the range, dominant trees include big-cone Douglas fir and Coulter pine as well as canyon live oak and California bay. On higher slopes, lodgepole, limber, ponderosa, Jeffrey, and sugar pines occur along with white fir, incense cedar, western juniper, and black and canyon oaks. The low elevation species are sensitive to fire, and thus only found on rocky areas where the geology itself is fire-resistant.

Fire danger

The fire danger in the foothills is very high. Almost all of the cities that the hills go through are cities for which CAL FIRE has made recommendations on Very High Fire Hazard Severity Zones.Cities for Which CAL FIRE Has Made Recommendations on Very High Fire Hazard Severity Zones (VHFHSZ)." CAL FIRE. N.p., n.d. Web. 06 Dec. 2012. There have been a number of wild fires in the foothills of the San Gabriel Valley, that is part of the area's natural environment. Global warming has occurred rapidly over the course of the past half-century. In California, less precipitation will occur as snow, meaning that less water is able to be stored in the snow-pack, and that dry summers could see even less water availability. Summertime peak temperatures will increase in many places. Fire "seasons" may become even longer. The declaration of fire season in California is actually a change in preparedness levels for the California Department of Forestry and Fire Protection. When weather patterns in an area of the state become warm and dry, and vegetation (fuels) are at a low moisture content point, Emergency response dispatch levels are typically increased, facilities are staffed 24 hours a day and additional firefighters are hired. When cooling weather, rain and snow are sufficient to reduce the fire threat, CAL FIRE then reduces its preparedness levels by releasing additional firefighters, closing some of the stations, and repositioning aircraft.Frequently Asked Questions." http://www.fire.ca.gov. N.p., n.d. Web. 6 Dec. 2012.

Notes

References

# "Cities for Which CAL FIRE Has Made Recommendations on Very High Fire Hazard Severity Zones (VHFHSZ)." CAL FIRE. N.p., n.d. Web. 06 Dec. 2012. # "Climate, Fire, and Habitat in Southern California." – Sustainable and Fire Safe Landscapes. N.p., n.d. Web. 05 Dec. 2012. # "Frequently Asked Questions." http://www.fire.ca.gov. N.p., n.d. Web. 6 Dec. 2012. # http://geology.campus.ad.csulb.edu. N.p., n.d. Web. 04 Dec. 2012. #"IE Communities at Risk Www.fireinformation.com." IE Communities at Risk Www.fireinformation.com. N.p., n.d. Web. 04 Dec. 2012. #"San Gabriel Valley." ROAD TRIP USA. N.p., n.d. Web. 04 Dec. 2012. {{DEFAULTSORT:Foothills San Gabriel Valley Geography of the San Gabriel Valley Greater Los Angeles San Gabriel Mountains Mountain ranges of Los Angeles County, California San Gabriel Valley

Geography

Foothills and hill ranges

Natural environments

Fire danger

See also

Notes

References