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 Barbara, Los Angeles, San Bernardino and Riverside counties; the Peninsular Ranges lie to the south. The name Transverse Ranges is due to their east–west orientation, making them transverse to the general northwest–southeast orientation of most of California's coastal mountains; the ranges extend from west of Point Conception eastward 500 kilometers into the Mojave and Colorado Desert. The geology and topography of the ranges express three distinct segments that have contrasting elevations, rock types, vegetation; the western segment extends to the San Gabriel Mountains and San Gabriel fault. The central segment includes; the eastern segment extends from the San Andreas fault eastward to the Colorado Desert. The central and eastern segments have the highest elevations.
Most of the ranges lie in the California chaparral and woodlands ecoregion. Lower elevations are dominated by chaparral and scrubland, while higher elevations support large conifer forests. Most of the ranges in the system are fault blocks, were uplifted by tectonic movements late in the Cenozoic Era. West of Tejon Pass, the primary rock types are varied, with a mix of sedimentary and metamorphic rocks, while regions east of the pass are dominated by plutonic granitic and metasedimentary rocks; the western and central segments of the Transverse Ranges are bounded to the north and east by the San Andreas Fault, which separates those segments from the Mojave Desert. The eastern segment bounds the southern Mojave Desert. Notable passes along the San Andreas fault include Tejon Pass, Cajon Pass, San Gorgonio Pass. Components of Transverse Ranges to the north and east of the fault include the San Bernardino Mountains, Little San Bernardino Mountains and Eagle Mountains; the western and southern boundaries are acknowledged to be the Pacific Ocean and the northern Channel Islands.
Onshore the Los Angeles Basin lies at the southern boundary of the western and central segments of the ranges. Major passes not along the San Andreas Fault include Gaviota Pass, San Marcos Pass, the Conejo Grade, Newhall Pass, Cahuenga Pass; the Transverse Ranges manifest themselves as a series of parallel ridges with an average height of 3,000–8,000 feet. The ranges are dissected by young, steep streams of low flow rate; the mountains are notable for being difficult to traverse. There are few passes that are sufficiently low or wide enough to accommodate significant volumes of traffic; this has resulted in situations where major cities are linked to the rest of the state by few roads. This results in significant traffic issues throughout Southern California when a pass has to be shut down due to heavy snow or construction. Major cities, such as Santa Barbara during the 2005 La Conchita landslide, may be cut off from timely road access to the rest of Southern California. Major peaks of the Transverse Ranges with at least 500 feet of prominence, listed by height: This segment begins at Point Conception in Santa Barbara County, include the Santa Ynez Mountains that run parallel to the coast behind Santa Barbara.
The western Transverse Ranges include the Topatopa Mountains and the Santa Susana Mountains of Ventura County and Los Angeles County, the Simi Hills, the Santa Monica Mountains that run along the Pacific coast behind Malibu, whose eastern portion are known as the Hollywood Hills, the Chalk Hills. The northern Channel Islands of California are part of the Transverse Ranges; the Ranges include the steep San Gabriel Mountains northeast of Los Angeles, the Verdugo Mountains, the Liebre-Sawmill Mountains, the San Rafael Hills, Puente Hills, San Jose Hills, Chino Hills. The San Bernardino Mountains, Little San Bernardino Mountains, the Pinto and Orocopia Mountains are within the eastern segment; the Mojave Desert and California's low desert, including the Coachella Valley, are at the eastern end of the ranges. Ranges north of the western segment that are nearly transverse but are part of the California Coast Ranges include the San Rafael Mountains and the Sierra Madre Mountains; the Tehachapi Mountains north of the Mojave Desert, although nearly transverse, are the southern end of the Sierra Nevada.
The climate in most of the range is Csb under the Köppen climate classification. Snow falls above 6,000 feet most winters, above 3,000 feet every few years, it is rare for elevations above 8,000 feet to go multiple winters without snow during severe droughts. Due to low humidity, the regional snow line lies at about 14,000–16,000 feet, above the highest elevation of the range.
Mount Tamalpais is a peak in Marin County, United States considered symbolic of Marin County. Much of Mount Tamalpais is protected within public lands such as Mount Tamalpais State Park, the Marin Municipal Water District watershed, National Park Service land, such as Muir Woods. Mount Tamalpais is the highest peak in the Marin Hills, which are part of the Northern California Coast Ranges; the elevation at the West Peak, where a radar dome stands, is between 2,560 feet and 2,580 feet. It stood over; the East Peak is at 2,571 feet. The East Peak was considered the highest point in the county, but now that claim is being disputed by those who believe the west peak is higher, but there is no corroboration of the claim on behalf of west peak from USGS or any other official body. The site ListsOfJohn has marked the west peak to be higher, but added a footnote that the east peak may be higher since the west peak summit was razed; the mountain is visible from the city of San Francisco and the East Bay region.
The majority of the mountain is contained in protected public lands, including Mount Tamalpais State Park, Muir Woods National Monument, the Mount Tamalpais Watershed. It adjoins the Golden Gate National Recreation Area as well as several Marin County Open Space Preserves; this provides nearly 40 miles of continuous publicly accessible open space. Some of the lower slopes of Mount Tamalpais fall within several cities and unincorporated communities of Marin County, including Mill Valley, Tamalpais-Homestead Valley, Stinson Beach, Kentfield; these areas are developed, consisting of low-density single-family homes. Like the rest of the California Coast Ranges, Mount Tamalpais is the result of uplift and folding of the North American plate as it slides along the Pacific Plate near the San Andreas fault zone. In 2004, a team of Penn State geoscientists suggested that a blind thrust fault, like the one that caused the infamous Northridge earthquake, lies beneath Mount Tamalpais; this idea was based on the steepness of Mount Tamalpais and of nearby Bolinas Ridge, such steepness on the visible surface being the result of blind thrust faults.
Another reason for the suggestion was that the San Andreas Fault creeps more south of Mount Tamalpais than it does in its sections north of Mount Tamalpais and in the Olema Valley, that the existence of a blind thrust fault may explain the different creeping velocities. If a blind thrust fault does exist under Mount Tamalpais, if it ruptures, it could be devastating to the North Bay, San Francisco, any other nearby locale resting on unstable earth and loose fill. Major Mount Tamalpais rockforms include serpentine evident in outcroppings near the summit and on the north side. A number of serpentine endemic plants grow in the serpentine soils in this part of the mountain. Since the steep slopes of Mount Tamalpais force out moisture from passing storms and/or fog, the mountain supports several year-round streams like Redwood Creek on the southern face of the mountain down into Muir Woods; the steep southeastern slopes of Mount Tamalpais drain to Arroyo Corte Madera del Presidio, which in turn discharges to Richardson Bay.
With its height, various faces, proximity to the ocean and bay, the mountain contains many microclimates, ranging from cool and foggy in lower ocean-facing valleys with their redwood forests, to hot and dry on the manzanita slopes and breezy at the summit, shady on the Douglas-fir-forested north slopes near Alpine Lake. Annual precipitation around Mount Tamalpais varies from around 27.5–31.5 inches in the drier, eastern foothills to about 59 inches near the Bolinas Ridge, close to the Pacific Ocean. Both Mount Tamalpais and the Bolinas Ridge force moisture out of the air efficiently, since the air is cooled as it ascends the steep mountain faces and thus Mount Tamalpais's western part is forested with tall redwoods and Douglas firs; the same fact holds for the steep, south-facing bowl canyon that Muir Woods is located in, with precipitation in Redwood Canyon at around 39.4–47.2 inches. As in San Francisco, most of the annual precipitation falls during the winter months. During cold, wet winter storms, the mountain regularly gets some snowfall, sometimes as much as 6 inches overnight, as observed in February 2001, March 2006, February 2011.
The region sometimes gets hit with strong Pacific storms that may topple trees, bring hurricane-force winds to exposed, barren areas like the Bolinas Ridge and the summit of Mount Tamalpais. In summer, the area gets no precipitation, except for fog drip that occurs in Muir Woods, the Bolinas Ridge and the western end of Mount Tamalpais, where summer fog and oceanic breezes are more prevalent. In contrast, the eastern foothills, sheltered from the oceanic breezes and fog, are drier, since the foothills force little moisture out of the air; this leads to the fact that the eastern slopes contain only oak, chaparral shrub, coastal sage scrub and sparse Douglas-fir forest. Coastal sage scrub occurs on some of the exposed coastal slopes. Temperatures on top of Mount Tamalpais are somewhat cooler than places next to the San Francisco Bay or the ocean due to elevation. In summer, the top of Mount Tamalpais may be warmer than the middle, foggy elevations due to a thermal inversion; the summer fog and breezes make locations on Mount Tamalpais, closer to the ocean, cooler than the blazing
California is a state in the Pacific Region of the United States. With 39.6 million residents, California is the most populous U. S. the third-largest by area. The state capital is Sacramento; the Greater Los Angeles Area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions, with 18.7 million and 9.7 million residents respectively. Los Angeles is California's most populous city, the country's second most populous, after New York City. California has the nation's most populous county, Los Angeles County, its largest county by area, San Bernardino County; the City and County of San Francisco is both the country's second-most densely populated major city after New York City and the fifth-most densely populated county, behind only four of the five New York City boroughs. California's $3.0 trillion economy is larger than that of any other state, larger than those of Texas and Florida combined, the largest sub-national economy in the world. If it were a country, California would be the 5th largest economy in the world, the 36th most populous as of 2017.
The Greater Los Angeles Area and the San Francisco Bay Area are the nation's second- and third-largest urban economies, after the New York metropolitan area. The San Francisco Bay Area PSA had the nation's highest GDP per capita in 2017 among large PSAs, is home to three of the world's ten largest companies by market capitalization and four of the world's ten richest people. California is considered a global trendsetter in popular culture, innovation and politics, it is considered the origin of the American film industry, the hippie counterculture, fast food, the Internet, the personal computer, among others. The San Francisco Bay Area and the Greater Los Angeles Area are seen as global centers of the technology and entertainment industries, respectively. California has a diverse economy: 58% of the state's economy is centered on finance, real estate services and professional, scientific and technical business services. Although it accounts for only 1.5% of the state's economy, California's agriculture industry has the highest output of any U.
S. state. California is bordered by Oregon to the north and Arizona to the east, the Mexican state of Baja California to the south; the state's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east, from the redwood–Douglas fir forests in the northwest to the Mojave Desert in the southeast. The Central Valley, a major agricultural area, dominates the state's center. Although California is well-known for its warm Mediterranean climate, the large size of the state results in climates that vary from moist temperate rainforest in the north to arid desert in the interior, as well as snowy alpine in the mountains. Over time and wildfires have become more pervasive features. What is now California was first settled by various Native Californian tribes before being explored by a number of European expeditions during the 16th and 17th centuries; the Spanish Empire claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its successful war for independence but was ceded to the United States in 1848 after the Mexican–American War.
The western portion of Alta California was organized and admitted as the 31st state on September 9, 1850. The California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom; the word California referred to the Baja California Peninsula of Mexico. The name derived from the mythical island California in the fictional story of Queen Calafia, as recorded in a 1510 work The Adventures of Esplandián by Garci Rodríguez de Montalvo; this work was the fifth in a popular Spanish chivalric romance series that began with Amadis de Gaula. Queen Calafia's kingdom was said to be a remote land rich in gold and pearls, inhabited by beautiful black women who wore gold armor and lived like Amazons, as well as griffins and other strange beasts. In the fictional paradise, the ruler Queen Calafia fought alongside Muslims and her name may have been chosen to echo the title of a Muslim leader, the Caliph. It's possible.
Know ye that at the right hand of the Indies there is an island called California close to that part of the Terrestrial Paradise, inhabited by black women without a single man among them, they lived in the manner of Amazons. They were robust of body with great virtue; the island itself is one of the wildest in the world on account of the craggy rocks. Shortened forms of the state's name include CA, Cal. Calif. and US-CA. Settled by successive waves of arrivals during the last 10,000 years, California was one of the most culturally and linguistically diverse areas in pre-Columbian North America. Various estimates of the native population range from 100,000 to 300,000; the Indigenous peoples of California included more than 70 distinct groups of Native Americans, ranging from large, settled populations living on the coast to groups in the interior. California groups were diverse in their political organization with bands, villages, on the resource-rich coasts, large chiefdoms, such as the Chumash and Salinan.
Trade, intermarriage a
Cache Creek (Sacramento River tributary)
Cache Creek is an 87-mile-long stream in Lake and Yolo counties, California. Cache Creek starts at the outlet of Clear Lake, it has two main tributaries: North Fork. The Capay Diversion Dam, west of Capay, diverts water for distribution throughout Yolo County using a network of canals. At the end of the Capay Valley, near Esparto, Cache Creek runs east into Sacramento Valley, ending in a settling basin east of Woodland, the overflow of which runs into the Sacramento River through a flood control canal. In addition to the recreational use of Clear Lake and Indian Valley Reservoir there are numerous trail-heads and campgrounds, including the Bear Valley wildflower hotspot. Bear Creek and Cache Creek run in a scenic canyon along State Route 16 in Colusa and Yolo county, including the Cache Creek Regional Park. Cache Creek provides white-water rafting, both in the spring when it is flooded, through the summer using the agricultural water flow; the entire area south of Route 20 and west of Route 16 is a wildlife preserve, hosting two herds of Tule Elk.
The name of the water body comes from Hudson's Bay Company trappers who cached their furs along the Sacramento River and smaller tributaries, one of which became known to them as Cache Creek. One of their camps, recognized by early settlers as French Camp, was situated in a grove of oaks on the north bank of Cache Creek one mile east of the present town of Yolo, California. Cache Creek was known to the Hudson's Bay Company trappers as Rivière la Cache. Cache Creek was temporarily blocked north of Rumsey by a landslide caused by the 1906 San Francisco earthquake: Our Rumsey correspondent mentions the fall of Cache Creek as a result of an earthquake shock Tuesday night; the water has continued to fall some since that date and in some places it is dry. Upon investigation by the officials of the Water Company it was found that a landslide had dammed the Creek near the Leonard ranch in Lake county.... The creek subsequently broke through. Cache Creek has two main tributaries: North Fork, Bear Creek.
Cache Creek begins at the south-east end of Clear Lake, flowing east to the dam which now controls the level of Clear Lake. The North Fork begins in Lake County in the Mendocino National Forest north of Upper Lake, it flows east, where it is joined by Bartlett Creek, is dammed by the Indian Valley Reservoir. It flows south along New Long Valley Road, turns east along State Route 20, which it crosses at the Cache Creek Recreation Area. Cache Creek runs north-east from the dam, behind Perkins Creek Ridge and over The Jams Waterfall before joining the North Fork about 2 miles east of the bridge over Route 20. Bear Creek starts in Bear Valley and runs south through a canyon until it meets Route 20, it runs east in parallel with Route 20 for a few miles, turns south, again cutting through a canyon following State Route 16 in Colusa and Yolo Counties. Meanwhile, Cache Creek cuts south-east between Cache Creek Ridge and Little Blue Ridge, joining Bear Creek at Route 16 near the junction of Lake and Yolo counties.
The combined Cache Creek continues in the canyon. The Capay Diversion Dam, west of Capay, diverts water for distribution throughout Yolo County using a 175-mile network of canals. At the end of the Capay Valley near Esparto Cache Creek runs east into Sacramento Valley, ending in a settling basin east of Woodland. If the Sacramento river is not in flood any overflow runs into the Tule Canal,continues as Prospect Slough and enters the Sacramento River at Cache Slough. If the Sacramento IS in flood the overflow from the settling basin is swept into the Yolo Bypass and Sacramento Bypass flood control system, emerging directly at Cache Slough. Water rights and flooding protection have been in dispute between Yolo and Lake Counties since the late 19th century; the Yolo County Flood Control & Water Conservation District has "an 1855 priority right to divert the natural flow of Cache Creek, 1912 priority right to store waters in Clear Lake to elevation 7.56 feet Rumsey Gauge for release and beneficial use."
Various decrees attempt to ensure a balance between the needs of the two counties, although high-water conditions can cause temporary disagreements. Under the Solano Decree Yolo holds appropriative rights for up to 150,000 acre feet per year from Clear Lake, all the water from the Indian Valley dam; the Cache Creek Dam on the South Fork of Cache Creek, five miles downstream from Clear Lake, was built to increase Clear Lake's capacity and to regulate outflow for downstream users of Cache Creek water. The dam was modified to include a 3 MW hydroelectric plant; the stream has a small capacity, less than a quarter of the amount the dam is able to release. There is a rock ledge a mile and a half downstream of Clear Lake, called the Grigsby Riffle, near the bridge on State Route 53; this ledge restricts the amount of water. The limited capacity of the stream means that it takes a long time to drain excess flow from Clear Lake, increasing the chance of flooding around the lake; the bottleneck is seen as a backup to prevent flooding downstream and Yolo County is prohibited from increasing the capacity of the channel by the Gopcevic and Bemmerly Decrees.
The Indian Valley dam on the North Fork of Cache Creek forms Indian Valley Reservoir. The dam's primary purpose is water storage for irrigation, but a 3
Eel River (California)
The Eel River is a major river, about 196 miles long, of northwestern California. The river and its tributaries form the third largest watershed in California, draining a rugged area of 3,684 square miles in five counties; the river flows northward through the Coast Ranges west of the Sacramento Valley, emptying into the Pacific Ocean about 10 miles downstream from Fortuna and just south of Humboldt Bay. The river provides groundwater recharge and industrial, agricultural and municipal water supply; the Eel River system is among the most dynamic in California because of the region's unstable geology and the influence of major Pacific storms. The discharge is variable; the river carries the highest suspended sediment load of any river of its size in the United States, in part due to the frequent landslides in the region. However, the river basin supports abundant forests – including some of the world's largest trees in Sequoia sempervirens groves – and one of California's major salmon and steelhead trout runs.
The river basin was populated by Native Americans before, for decades after the European settlement of California. The region remained little traveled until 1850, when Josiah Gregg and his exploring party arrived in search of land for settlement; the river was named after they traded a frying pan to a group of Wiyot fishermen in exchange for a large number of Pacific lampreys, which the explorers thought were eels. Explorers' reports of the fertile and timbered region attracted settlers to Humboldt Bay and the Eel River Valley. Starting in the late 19th century the Eel River supported a large salmon canning industry which began to decline by the 1920s due to overfishing; the Eel River basin has been a significant source of timber since the days of early settlement and continues to support a major logging sector. The river valley was a major rail transport corridor throughout the 20th century and forms part of the route of Redwood Highway. Since the early 20th century, the Eel River has been dammed in its headwaters to provide water, via interbasin transfer, to parts of Mendocino and Sonoma Counties.
During the 1950s and 1960s, there was great interest in building much larger dams in the Eel River system, in order to provide water for the State Water Project. Although the damming would have relieved pressure on California's overburdened water systems, it stirred up decades of controversy, as some of the proposals made little economic sense and would have been detrimental to an ailing salmon run; the Eel was granted federal Wild and Scenic River status in 1981, formally making it off limits to new dams. Logging, road-building and other human activities continue to affect the watershed's ecology; the Eel River originates on the southern flank of 6,740-foot Bald Mountain, in the Upper Lake Ranger District of the Mendocino National Forest in Mendocino County. The river flows south through a narrow canyon in Lake County before entering Lake Pillsbury, the reservoir created by Scott Dam. Below the dam the river flows west. At the small Cape Horn Dam about 15 miles east of Willits, water is diverted from the Eel River basin through a 1-mile tunnel to the Russian River, in a scheme known as the Potter Valley Project.
Below the dam the river turns north, flowing through a long isolated valley, receiving Outlet Creek from the west and the Middle Fork Eel River from the east at Dos Rios. About 20 miles downstream, the North Fork Eel River – draining one of the most rugged and remote portions of the watershed – joins from the east. Between the North and Middle Forks the Round Valley Indian Reservation lies east of the Eel River. After this confluence the Eel flows through southwestern Trinity County, past Island Mountain, before entering Humboldt County near Alderpoint; the river cuts in a northwesterly direction across Humboldt County, past a number of small mountain communities including Fort Seward. The South Fork Eel River joins from the west, near Humboldt Redwoods State Park and the town of Weott. Below the South Fork the Eel flows through a wider agricultural valley, past Scotia and Rio Dell, before receiving the Van Duzen River from the east. At Fortuna, the river turns west across the coastal plain and enters the Pacific via a large estuary in central Humboldt County, about 15 miles south of Eureka.
The Northwestern Pacific Railroad tracks follow the Eel River from Outlet Creek, about 7 miles above Dos Rios, to Fortuna. The railroad has been out of service since 1998 due to concerns of flooding damage. U. S. Route 101 runs along the South Fork Eel River and the lower Eel River below the South Fork. Average flow of the Eel River varies due to its location, which places it more or less directly in the path of Pineapple Express-type winter storms. Wet season flows can be enormous, while the summer and early autumn provide only minimal precipitation, if any, allowing the sometimes mighty river to slow to a trickle. At the mouth, the Eel River produces an estimated annual runoff of 6.9 million acre feet per year, or about 9,500 cu ft/s. The Eel's maximum recorded flow of 936,000 cu ft/s on December 23, 1964 was the largest peak discharge of any California river in recorded history, one of the largest peaks recorded in the world relative to the size of its drainage basin. In contrast, during the dry months of July through September, the river achieves nearly zero flow.
The lowermost United States Geological Survey
A summit is a point on a surface, higher in elevation than all points adjacent to it. The topographic terms acme, apex and zenith are synonymous; the term top is used only for a mountain peak, located at some distance from the nearest point of higher elevation. For example, a big massive rock next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for the quantities, are considered subsummits of the higher peak, are considered part of the same mountain. A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may refer to the highest point along a line, trail, or route; the highest summit in the world is Everest with height of 8844.43 m above sea level. The first official ascent was made by Sir Edmund Hillary, they reached the mountain`s peak in 1953. Whether a highest point is classified as a summit, a sub peak or a separate mountain is subjective; the UIAA definition of a peak is.
Otherwise, it's a subpeak. In many parts of the western United States, the term summit refers to the highest point along a road, highway, or railroad. For example, the highest point along Interstate 80 in California is referred to as Donner Summit and the highest point on Interstate 5 is Siskiyou Mountain Summit. A summit climbing differs from the common mountaineering. Summit expedition requires: 1+ year of training, a good physical shape, a special gear. Although a huge part of climber’s stuff can be left and taken at the base camps or given to porters, there is a long list of personal equipment. In addition to common mountaineers’ gear, Summit climbers need to take Diamox and bottles of oxygen. There are special requirements for crampons, ice axe, rappel device, etc. Geoid Hill – Landform that extends above the surrounding terrain Nadir Summit accordance Peak finder Summit Climbing Gear List
The Peninsular Ranges are a group of mountain ranges that stretch 1,500 km from Southern California to the southern tip of the Baja California Peninsula. Elevations range from 500 to 10,834 feet; the Peninsular Ranges include the Santa Ana Mountains and other mountains and ranges of the Perris Block, San Jacinto and Laguna ranges of southern California continuing from north to south with the Sierra de Juárez, Sierra de San Pedro Mártir, Sierra de San Borja, Sierra de San Francisco, Sierra de la Giganta, Sierra de la Laguna in Baja California. Palomar Mountain, home to Palomar Observatory, is in the Peninsular Ranges in San Diego County, as is Viejas Mountain and the San Ysidro Mountains; the Peninsular ranges run predominantly north-south, unlike the Transverse Ranges to their north, which run east-west. Rocks in the ranges are dominated by Mesozoic granitic rocks, derived from the same massive batholith which forms the core of the Sierra Nevada Mountains in California, they are part of a geologic province known as the Salinian Block which broke off the North American Plate as the San Andreas Fault and Gulf of California came into being.
Between this set of ranges and the Transverse Ranges is the complex Malibu Coast—Santa Monica—Hollywood fault, which exists as the border between these two geologically unitary provinces. Most of the Peninsular Ranges are in the Nearctic ecozone. Several terrestrial ecoregions cover portions of the Peninsular Ranges. On western-coast side of the northern portion of the ranges the California montane chaparral and woodlands sub-ecoregion of the California chaparral and woodlands ecoregion covers in southern California and northern Baja California. On western-coast side of the southern portion of the ranges the Baja California desert ecoregion covers in the southern portion of the Peninsular Ranges in Baja California and Baja California Sur. On eastern side of northern ranges, the Sonoran Desert ecoregion covers southeastern California and northeastern Baja California as far south as the town of Loreto, Baja California Sur. On the eastern side of the Laguna Mountains in San Diego County the Anza-Borrego Desert State Park is known for its springtime profusion of Colorado Desert wildflowers.
On eastern-Gulf of California side of the southern portion of the ranges the Gulf of California xeric scrub ecoregion covers the range in Baja California Sur. The higher portions of the Peninsular Ranges the west-facing slopes, are home to coniferous and mixed evergreen forests. Cleveland National Forest covers much of the higher Southern California Peninsular Ranges; the vegetation includes oak forests of Jeffrey Pine and Coulter Pine. The Sierra Juarez and San Pedro Martir pine-oak forests cover upper slopes of Sierra Juarez and San Pedro Martir ranges in Baja California; these isolated forests, predominantly Tamarack Pine, Sugar Pine, Parry Pinyon, White Fir, California Incense Cedar, junipers. Oak species include Coast Live Oak, Engelmann Oak, Canyon Live Oak, Baja Oak; these higher portions of the Peninsular Ranges harbor many endemic species. Southern Baja California Sur is part of the Neotropic ecozone; the southern end of the Baja California Peninsula, including the Sierra de la Laguna Peninsular Range, was an island, evolved in relative isolation from the northern part of the peninsula and ranges.
Its flora and fauna share many affinities with southern Central America. It includes three distinct ecoregions, the Sierra de la Laguna dry forests, Sierra de la Laguna pine-oak forests, San Lucan xeric scrub. Peninsular Ranges index Transverse Ranges List of mountain ranges