| Santa Monica Mountains | |
|---|---|
 Malibu Canyon (with theRindge Dam at lower right) in the Santa Monica Mountains | |
| Highest point | |
| Peak | Sandstone Peak |
| Elevation | 3,111 ft (948 m) |
| Geography | |
 | |
| Country | United States |
| State | California |
| Counties | |
| Range coordinates | 34°7′13.023″N118°55′54.348″W / 34.12028417°N 118.93176333°W /34.12028417; -118.93176333 |
| Parent range | Transverse Ranges |
| Borders on | |
TheSanta Monica Mountains are a coastal mountain range inSouthern California, next to thePacific Ocean. It is part of theTransverse Ranges.[1] TheSanta Monica Mountains National Recreation Area encompasses this mountain range. Because of its proximity to densely populated regions, it is one of the most visited natural areas in California.
The range extends approximately 40 miles (64 km) east-west[2] from theHollywood Hills inLos Angeles toPoint Mugu inVentura County.[3] The western mountains, separating theConejo Valley fromMalibu, suddenly end at Mugu Peak[4] as the rugged, nearly impassible shoreline gives way totidal lagoons andcoastal sand dunes of thealluvialOxnard Plain. The mountain range contributed to the isolation of this vastcoastal plain before regular transportation routes reached western Ventura County. The eastern mountains form a barrier between theSan Fernando Valley and theLos Angeles Basin, separating "the Valley" on the north and west-central Los Angeles on the south. The Santa Monica Mountains areparallel to theSanta Susana Mountains, which are located directly north of the mountains across the San Fernando Valley.
The range is of moderate height, with no particularly craggy or prominent peaks outside the Sandstone Peak and Boney Mountains area. While often rugged and wild, the range hosts a substantial amount of human activity and development. Houses, roads, businesses, and recreational centers are dotted throughout the Santa Monica Mountains.
A number of creeks in the Santa Monica Mountains are part of theLos Angeles River watershed. Beginning at the western end of theSan Fernando Valley, the river runs to the north of the mountains. After passing between the range and theVerdugo Mountains it flows south aroundElysian Park, defining the easternmost extent of the mountains.
The Santa Monica Mountains have more than 1,000archeology sites of significance, primarily from theCalifornian Native American cultures of theTongva andChumash people.[5] The mountains were part of their regional homelands for over eight thousand years before the arrival of theSpanish.[6] TheSpanish mission system had a dramatic impact on their culture, and by 1831 their population had dropped from over 22,000 to under 3,000.[7]
Geologists consider the northernChannel Islands to be a westward extension of the Santa Monicas into thePacific Ocean. The range was created by repeated episodes of uplifting and submergence by theRaymond Fault, which created complex layers ofsedimentary rock, some containing fossils of invertebrates and fish.Volcanic intrusions have been exposed, including the poorly namedandesitic[8] "Sandstone Peak", which is the highest point in the range at 3,111 feet (948 m).Malibu Creek, which eroded its own channel while the mountains were slowly uplifted, bisects the mountain range.
The Santa Monica Mountains have dry summers with frequent coastalfog on the ocean (south) side of the range and rainy, cooler winters. In the summer, the climate is quite dry (except for the coastal fog), which makes the range prone towildfires, especially during dry "Santa Ana" wind events.
Snow is unusual in the Santa Monica Mountains, since they are not as high as the nearbySan Gabriel Mountains. The lower slopes of the range average between 15 and 20 inches (380 and 510 mm) of rain per year, while the higher slopes of the central and western Santa Monica Mountains average 22 to 27 inches (560 to 690 mm) of rain per year. The bulk of the rain falls between November and March. The higher rainfall in the central and western parts of the range results in more widespread woodlands (with oak, sycamore, walnut, bay laurel, alder and other trees) than the eastern part of the range, where trees are usually restricted to the stream courses.
On January 17, 2007, an unusually cold storm brought snow in the Santa Monica Mountains.[9][10] The hills above Malibu picked up three inches (eight centimeters) of snow - the first measurable snow in fifty years. Snow was reported onBoney Peak in the winter of 2005; and in March 2006, snow also fell on the summit of the mountain. Snow also fell on the peak of Boney Peak in late December 2008.[citation needed] The latest recorded snowfall in the area was in February 2019, when an unusual amount of snowfall accumulated in low passes in the mountains. That storm system also brought rare snowfall to the Los Angeles area. Heavygraupel was recorded inMalibu Canyon on January 23, 2021. It accumulated as low as 400 feet in elevation.[citation needed]
In the Santa Monica Mountains, when the fuels, seasonal drought, wind, and terrain combine with an ignition, a major wildfire occurs. These fires are large, wind-driven canopy fires that consume the above ground vegetation and often cause major property damage and home losses.[11]
In 2018, theWoolsey Fire burned through 88% of the federal parkland resulting in trails being closed for months.[12] The fire, which was three times larger than the biggest fire ever before in the mountains, burned over 40% of the natural area in the Santa Monicas.[13] A restoration plan was developed to plant 100,000 trees, shrubs and grasses of 25 different species.[14]
Much of the mountains are located within theSanta Monica Mountains National Recreation Area. Preservation of lands within the region are managed by theSanta Monica Mountains Conservancy, theNational Park Service, theCalifornia State Parks, and County and Municipal agencies. The Santa Monica Mountains face pressure from local populations as a desirable residential area, and in the parks as a recreational retreat and wild place that's increasingly rare in urbanLos Angeles. In 2014 theCalifornia Coastal Commission and theLos Angeles County Board of Supervisors approved the Santa Monica Mountains Local Coastal Program, aland-use plan that will distinguish between the private lands that need strict protection and property that could be developed in strict conformance with this detailed plan.[18]
Over twenty individual state and municipal parks are in the Santa Monica Mountains, including:Topanga State Park,Leo Carrillo State Park,Malibu Creek State Park,Point Mugu State Park,Will Rogers State Historic Park,Point Dume State Beach,Griffith Park,Marvin Braude Mulholland Gateway Park,Charmlee Wilderness Park,[19]Franklin Canyon Park,Runyon Canyon Park,King Gillette Ranch Park,[20] andParamount Ranch Park.[21]
TheSatwiwa Native American Indian Culture Center inNewbury Park, California is located within theSanta Monica Mountains National Recreation Area. The area was purchased by theU.S. National Park Service in 1980.[22] TheRosewood Trail nearStagecoach Inn, which leads toAngel Vista is an access point in Newbury Park.
At the eastern end of the Santa Monica Mountains areGriffith Park andElysian Park. Griffith Park is separated from the rest of the Santa Monica Mountains to the west by theCahuenga Pass, over which the101 Freeway (also called the Hollywood Freeway) passes from theSan Fernando Valley intoHollywood. Elysian Park is in the easternmost part of the mountains and is bordered by theLos Angeles River to the east andDowntown Los Angeles nearby to the south.
The Rim of the Valley Trail is a plan in progress for accessing and connecting the parkland and recreational areas of the mountains surrounding theConejo,San Fernando,Simi, andCrescenta Valleys. With trailheads in the mountains and valleys, it would link them through existing and new: walking, hiking, equestrian, and mountain biking trails; parklands; andconservation easements. The Rim of the Valley project also has the goal to protect flora and faunahabitats andwildlife corridors between the Santa Monica Mountains and the inland ranges.[23][24][25][26]
The range is host to a variety of wildlife. Common mammals in the range includemule deer,coyotes,bobcats,striped skunks,raccoons, several native bat species,brush rabbits, and many rodents includingCalifornia voles,western gray squirrels,dusky-footed anddesert woodrats,western harvest andCalifornia pocket mice,Botta's pocket gophers, and pacific kangaroo rats.[27]
Themountain lion population is challenged because the Santa Monica Mountains are isolated and not large enough for weaned cubs to find their own territory.[28][29][30][31] The primary cause of the decline is due to a combination of traffic-related mortality,[32][33]anti-coagulants ingested from human poisoned prey, and attacks by other, more dominant mountain lions.[34] TheWallis Annenberg Wildlife Crossing will bridge theVentura Freeway which acts as a barrier in thewildlife corridor between theSimi Hills to the north and the Santa Monica Mountains to the south.[35] The National Park Service has recorded a dozen mountain lions struck and killed by motorists on this section of freeway since they began tracking them in 2002,[36] with most mountain lions turning back without attempting to cross,[37] and onlyone who was repeatedly able to safely cross.[38] In 2020, wildlife biologists found the first evidence of physical abnormalities in the isolated population, most likely due to alack of genetic diversity.[39]
Since 2002, theNational Park Service has tracked more than 100mountain lions in the Santa Monica Mountains and other nearby ranges.P-22 resided in Griffith Park in the eastern end of the Santa Monica Mountains until his death in 2022. His father,P-1, was thedominant male for almost all of the rest of the range, until he was replaced byP-12 andP-27, P-12 later being replaced byP-45. Other mountain lions, includingP-2,P-64, and many others, have lived in the range as well.[40]
The National Park Service also tracksbobcats andblack bears in the Santa Monica Mountains. More than 350 bobcats have been tracked since 1996,[41] as have two bears:BB-12 andYellow 2291. These bears along with Yellow 2291's three offspring are the only bears documented in the Santa Monica Mountains in more than twenty years.[42][43]
Over 380 native bird species call the Santa Monica Mountains home.[44] Abundant native song birds species include theBushtit,California Scrub Jay,House Finch,Lesser Goldfinch,Cliff Swallow,Red-winged Blackbird,Oak Titmouse,Song Sparrow,California Towhee,Spotted Towhee,House Wren, andBlack Phoebe.Red-Tailed Hawks,Sharp-shinned Hawks,Red-shouldered Hawks,Northern Harriers,American Kestrels,Great Horned Owls, andWestern Screech-Owls are among common raptors in the area.White-tailed kites,Bald Eagles,Golden Eagles,[45][46] andBurrowing Owls have also been sighted.[47] In addition to these residential species, many bird species pass through the Santa Monica Mountains as they travel along thePacific Flyway includingBrown Pelicans,Rufous Hummingbirds,Canada Geese,[48]Bonaparte's Gulls, andElegant Terns.[49][27]
Native fish found in the Santa Monica Mountains include tidewater gobies,arroyo chub, andpacific lamprey. Additionally, Malibu creek is home to the southernsteelhead trout, which is an endangered species.[50][51]
Snakes are common but only occasionally seen: theSouthern Pacific rattlesnake (the only venomous species), mountain kingsnake,California kingsnake,gopher snake, andgarter snake. The mountains are also home to thewestern fence lizard and thecoastal whiptail. The population ofred-legged frogs is small and isolated, and was impacted by theWoolsey Fire that swept through the area in November 2018.[52]
The Santa Monica Mountains are in theCalifornia chaparral and woodlandsecoregion, and includes theCalifornia oak woodland andsouthern coastal sage scrubplant community, and are covered by hundreds of local plant species, some of which are very rare orendemic, and others which are widespread and have become popular horticultural ornamentals.Dudleya verityi is a rare species ofsucculent plant known by the common name "Verity's liveforever". This species is endemic to Ventura County and is found only on one edge of the Santa Monica Mountains, where it occurs in coastal sage scrub habitat.[53] The most common trees in the mountains are oak and sycamore. TheCalifornia black walnut, endemic to California, grows on the northern side of the mountains in the Valley and Griffith Park. Other species include willow and alder (along stream courses) and bay laurel. Several species of ferns (including large sword ferns) are found in wetter, shady areas throughout the range, especially near streams.
Manyinvasiveweeds have colonized the mountain habitats which can bring about significant changes in the ecosystems by altering the native plant communities and the processes that support them. These non-native plants include annualMediterranean grasses,Spanish broom (Genista juncea), andyellow starthistle (Centaurea solstitialis). In creeksideriparian habitats are found plants such asgiant cane (Arundo donax),German ivy (Delairea odorata),blue periwinkle (Vinca major), andivy (Hedera spp.).
More frequent fires have created conditions favorable to invasive plants. The 2018Woolsey Fire burned through 88% of the federal parkland.[54] The fire, which was three times larger than the biggest fire ever before in the mountains, burned over 40% of the natural area in the Santa Monicas.[55] The fire created a challenge to native plants asblack mustard with bright yellow flowers quickly established itself as awet winter followed the fire.[56] The mustard plants will also provide fuel for the next fires.[57]
TheNew Zealand mud snail is an invasive species found in the Santa Monica Mountains, that pose a serious threat to native species, complicating efforts to improve stream-water quality for the endangeredsteelhead.[58] Within a period of four years, the snails expanded from their first known population in Medea Creek inAgoura Hills to nearly 30 other stream sites. Researchers at the Santa Monica Bay Restoration Commission believe the snails' expansion may have been expedited after the mollusks traveled from stream to stream on the gear of contractors and volunteers.[59]
Cahuenga Pass, present-day site ofU.S. Route 101, is the easiest pass through the range connecting theLos Angeles Basin to theSan Fernando Valley. In the 1800s, two battles were fought there, and theTreaty of Cahuenga was signed nearby. In Hollywood's heyday, movie studios were found clustered on both sides of the highway.
Sepulveda Pass is the main north–south pass to the west, connecting theWestside toSherman Oaks via theSan Diego Freeway (I-405) andSepulveda Boulevard.
Other passes between the Sepulveda and Cahuenga passes include:Laurel Canyon Boulevard,Coldwater Canyon Avenue, andBeverly Glen Boulevard. West of the Sepulveda Pass areTopanga Canyon Boulevard (SR 27),Malibu Canyon Road,Kanan Road/Kanan Dume Road, andDecker Canyon Road.
Mulholland Drive runs much of the length of the Santa Monica Mountains, from Cahuenga Pass toWoodland Hills, although it is not open to motor vehicles west ofEncino. TheMulholland Highway runs from Woodland Hills to Sequit Point at thePacific Ocean.
The eastern end of the range, located in the City of Los Angeles, is more intensively developed than the western end. The city of Malibu runs between the coast and the leading mountain ridge, from Topanga Canyon in the east toLeo Carrillo State Park in the west.
Communities along the north slope of the mountains include (from east to west):
Communities along the south slope of the mountains include (from east to west):
| Peak | Height | Notes | |
|---|---|---|---|
| US | SI | ||
| Sandstone Peak[60] | 3111 ft | 948 m | also known asMount Allen, rising nearly a kilometer high |
| Tri-Peaks | 3010 ft | 917 m | |
| Exchange Peak | 2950 ft | 899 m | |
| Conejo Peak | 2854 ft | 870 m | |
| Boney Peak[61] | 2825 ft | 861 m | |
| Castro Peak[62] | 2824 ft | 861 m | highest peak in the eastern end of the range |
| Saddle Peak[63] | 2805 ft | 855 m | |
| Calabasas Peak[64] | 2165 ft | 660 m | |
| Temescal Peak | 2126 ft | 648 m | |
| Ballard Mountain[65] | 2,039 ft | 631 m | recognizes John Ballard, an early black pioneer |
| San Vicente Mountain[66] | 1965 ft | 599 m | former site of aNike missile base, now aCold War park |
| Clarks Peak[67] | 1965 ft | 599 m | |
| Mesa Peak[68] | 1844 ft | 562 m | |
| Cahuenga Peak[69] | 1820 ft | 555 m | |
| Brents Mountain[70] | 1713 ft | 522 m | |
| Mount Lee[71] | 1640 ft | 500 m | theHollywood Sign is on the south slope, at exactly half a kilometer high |
| Mount Hollywood[72] | 1625 ft | 495 m | inGriffith Park;Griffith Observatory is on the south slope |
| Mount Chapel | 1622 ft | 494 m | |
| Mount Bell | 1587 ft | 484 m | |
| La Jolla Peak[73] | 1567 ft | 478 m | |
| Laguna Peak[74] | 1457 ft | 444 m | theinstrumentation capping this peak servesNaval Base Ventura County below |
| Mugu Peak[4] | 1266 ft | 386 m | the westernmost peak in the range, rising directly from the beach |
This article incorporatespublic domain material fromFire Regime & History - Santa Monica Mountains National Recreation Area. U.S. National Park Service. June 7, 2022. RetrievedJuly 10, 2022.
{{cite web}}: CS1 maint: numeric names: authors list (link) This article incorporatespublic domain material fromCalifornia Red-Legged Frogs: Santa Monica Mountains National Recreation Area.National Park Service. RetrievedJuly 12, 2021.
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