The San Jose Hills are a 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 ...

in eastern Los Angeles County, California, marking the border between the San Gabriel Valley and the

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 ...

. It includes portions of

Covina Covina is a city in Los Angeles County, California, United States, about east of downtown Los Angeles, in the San Gabriel Valley. The population was 51,268 according to the 2020 census, up from 47,796 at the 2010 census. The city's slogan, "On ...

West Covina West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth. Etymology The word "west" is a Germanic word passed into some R ...

Walnut A walnut is the edible seed of a drupe of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, '' Juglans regia''. Although culinarily considered a "nut" and used as such, it is not a true ...

, Pomona, and San Dimas. To the south, the valley of San Jose Creek (a line followed by the

Pomona Freeway Pomona may refer to: Places Argentina * Pomona, Río Negro Australia * Pomona, Queensland, Australia, a town in the Shire of Noosa * Pomona, New South Wales, Australia Belize * Pomona, Belize, a municipality in Stann Creek District Mexico * ...

) separates the San Jose Hills from the

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. ...

and Chino Hills.

History

The

Tongva The Tongva ( ) are an Indigenous people of California from the Los Angeles Basin and the Southern Channel Islands, an area covering approximately . Some descendants of the people prefer Kizh as an endonym that, they argue, is more historically ...

village of Tooypinga was located at the base of the San Jose Hills. The village was destroyed by Spanish soldiers prior to 1785 as part of a raid, who frequently conducted sweeps of the

Los Angeles Basin The Los Angeles Basin is a sedimentary Structural basin, basin located in Southern California, in a region known as the Peninsular Ranges. The basin is also connected to an wikt:anomalous, anomalous group of east-west trending chains of mountai ...

abducting children to San Gabriel Mission and raping women.

Geology

The San Jose Hills are part of the geologic history of

Southern California Southern California (commonly shortened to SoCal) is a geographic and 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 populous urban a ...

. The San Gabriel Mountains (the Transverse ranges located north of the San Jose Hills) were uplifted by tectonic force as a result of the colliding Pacific and North American plates more than a billion years ago. This tectonic pressure created deeply fractured and fissured sheets of rock that began to shift direction about 25 million years ago. Gradually, a portion of this fissured rock began to uplift from the ocean, forming the

. Further folding and fissures helped form other uplifts that include both the San Jose Hills and Puente Hills. These hills, prone to erosion, were formed with their domed appearance while still submerged under water. The San Jose Hills Fault has the possible magnitude of 6.0 to 6.5 and last was active in 1990. The San Jose Hills' highest point is Buzzard Peak at . The highest elevations are composed of

conglomerate rock Conglomerate () is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contains a matrix of finer-grained sediments, such as sand, silt, or clay, which fill ...

with small, shallow patches of soil. At the bases, silty clay loam dominates. These geologic conditions restrain water absorption towards the rockier higher elevations, which allow runoff to hydrate the base, creating a more habitable (friendly) environment for plants. Because of the transverse (east-west) orientation of the range, this effect is pronounced on the north slope due to the lower rates of evaporation caused by sunlight directed from the south.

Plant communities and wildlife

The San Jose Hills are diverse with unique and rare plant communities. The dominant plant community is

coastal sage scrub Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is ...

, known for its high adaptations for long dry summers and is drought deciduous. Prickly-pear cactus can also be found there. Above , chaparral makes its appearance, which differs from the sage scrub by being evergreen. Along the northern slopes, especially in the cracks and valleys, one can find coast oak and Southern California black walnut woodlands. Southern California black walnut woodlands are increasingly rare and threatened. The largest strands of this community are in the San Jose Hills and

to the south. Mammals, birds, reptiles, and amphibians are very diverse in both the San Jose Hills and surrounding San Gabriel Valley. Mammals in the San Jose Hills include

bobcats The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the IUC ...

coyotes The coyote (''Canis latrans'') is a species of canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological nich ...

gray fox The gray fox (''Urocyon cinereoargenteus''), or grey fox, is an omnivorous mammal of the family Canidae, widespread throughout North America and Central America. This species and its only congener, the diminutive island fox (''Urocyon littor ...

skunks Skunks are mammals in the family Mephitidae. They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Different species of skunk vary in appearance from black-and-white to brown, cream or ging ...

opossums Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 93 species in 18 genera. Opossums originated in South America and entered North A ...

squirrels Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squ ...

, and other rodents. The bird diversity is exceptional, and notable species include

California quail The California quail (''Callipepla californica''), also known as the California valley quail or Valley quail, is a small ground-dwelling bird in the New World quail family. These birds have a curving crest or '' plume'', made of six feathers, tha ...

, least

Bell's vireo Bell's vireo (''Vireo bellii'') is a songbird that migrates between a breeding range in Western North America and a winter range in Central America. It is dull olive-gray above and whitish below. It has a faint white eye ring and faint wing bar ...

, coastal California gnatcatcher,

grasshopper sparrow The grasshopper sparrow (''Ammodramus savannarum'') is a small New World sparrow. It belongs to the genus '' Ammodramus,'' which contains three species that inhabit grasslands and prairies. Although sometimes found in crop fields and they will re ...

southwest willow flycatcher The willow flycatcher (''Empidonax traillii'') is a small insect-eating, neotropical migrant bird of the tyrant flycatcher family. There are four subspecies of the willow flycatcher currently recognized, all of which breed in North America (inc ...

, and

red-tailed hawk The red-tailed hawk (''Buteo jamaicensis'') is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members wit ...

. Reptiles and amphibians include various lizards and snakes, the

California red-legged frog The California red-legged frog (''Rana draytonii'') is a species of frog found in California (USA) and northern Baja California (Mexico). It was formerly considered a subspecies of the northern red-legged frog (''Rana aurora''). The frog is an IU ...

, southwestern arroyo toad, southwestern pond turtle, and other frogs and salamanders.

Culture and recreation

On the most northeastern border,

Fairplex Fairplex has been the home of the L.A. County Fair since 1922. Known prior to 1984 as the Los Angeles County Fairgrounds, it is located in the city of Pomona, California. The L.A. County Fair is held during the month of May since 2022, but the fa ...

(Los Angeles County Fairgrounds) offers an annual

L.A. County Fair The Los Angeles County Fair is an annual county fair. It was first held on October 17, 1922, and ran for five days through October 21, 1922, in a former beet field in Pomona, California. Highlights of the fair's first year were harness racing, ...

and other events throughout the year. Fairplex is also the location of both the Los Angeles County Railroad Museum and the

Wally Parks NHRA Motorsports Museum The Wally Parks NHRA Motorsports Museum houses a collection of memorabilia, automobiles, and motorcycles related to the sport of hot-rodding. It is located on the edge of the Los Angeles County Fairplex. History The museum was created by a grou ...

. Automotive racing enthusiasts can enjoy adjacent Pomona Raceway-Dragstrip. Two parks with significant natural areas are located in the eastern portion of the San Jose Hills; Ganesha Park include four picnic pavilions, a community center, amphitheater style band Shell, Olympic size swimming pool with slide, basketball courts, two lighted tennis courts, wildlife and hiking areas, and restroom facilities. Frank G. Bonelli park has Puddingstone Lake used for swimming, water skiing, wind surfing, and sailing. The lake is also stocked with trout, bluegill, catfish, and large-mouth bass.

Raging Waters Raging Waters are a chain of four water theme parks in Sacramento, San Dimas, San Jose, California, and Sydney, Australia. The parks are operated by Palace Entertainment and owned by its parent company Parques Reunidos, but they each contain d ...

, a water theme park, is located at the north end of the lake. There are boat rentals, hot tubs, an equestrian center and a wedding chapel. Bonelli park facilities include vehicle camp sites, trails for hiking, biking and horseback riding, play equipment, gazebos, and group rental picnic areas. East of Bonelli park is Mountain Meadows Golf Course, and on the west, Via Verde Country Club, the later that is south of Walnut Creek Park, a small park along

Walnut Creek A walnut is the edible seed of a drupe of any tree of the genus ''Juglans'' (family Juglandaceae), particularly the Persian or English walnut, ''Juglans regia''. Although culinarily considered a "nut" and used as such, it is not a true bo ...

(which drains both Puddingstone and nearby San Gabriel Mountains into the San Gabriel River). Several large institutions of higher education are located in the hills. These include the California Polytechnic State University, Pomona (Cal Poly Pomona); Mount San Antonio College ( Mt. SAC), and Pacific West Bible College. The Voorhis Ecological Reserve in the northwest part of the Cal Poly Pomona campus and contains 31 ha of

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 ...

. Biotrek is an educational program ran by the Biological Sciences Department. Biotrek includes a Rainforest greenhouse, a native plant garden, aquatic environments, and laboratories. Mt. Sac has a native

Wildlife Sanctuary A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or o ...

. Interment is provided by Forest Lawn Memorial Park and Mortuary. Near the Grand Avenue Corridor, Heritage Gardens Historical Park, located on the north slope, was recently redeveloped to include new hiking trails. Walnut Ranch Park can be found on the south slope. Along Citrus Avenue, one can find South Hills Country Club. Three parks exists along the south slopes: Shadow Oak Park, Creekside Park, and Gringrich Park. On the western portion of the hills is the Industry Hills Recreation Center and smaller Rimgrove and Woodgrove parks. Just east of Azusa Avenue, along the north slopes is Galster Wilderness Park with its new Galster Park Nature Center operated by the San Gabriel Mountains Regional Conservancy and of Walnut Woodland. The southern slope is

's newest development,

Big League Dreams Big or BIG may refer to: * Big, of great size or degree Film and television * ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks * '' Big!'', a Discovery Channel television show * ''Richard Hammond's Big'', a television show present ...

. This mega-sports complex was built on top of a superfund site, the old BKK landfill.

References

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History

Geology

Plant communities and wildlife

Culture and recreation

References

External links