San Andreas Fault
The San Andreas Fault is a continental transform fault that extends roughly 800 miles through California. It forms the boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip. The fault was first identified in 1895 by Professor Andrew Lawson of UC Berkeley and it is often described as having been named after San Andreas Lake, a small body of water that was formed in a valley between the two plates. However, according to some of his reports from 1895 and 1908, following the 1906 San Francisco earthquake, Lawson concluded that the fault extended all the way into southern California. In 1953, geologist Thomas Dibblee astounded the scientific establishment with his conclusion that hundreds of miles of lateral movement could occur along the fault. A project called the San Andreas Fault Observatory at Depth near Parkfield, Monterey County, is drilling into the fault to improve prediction and this is the approximate location of the epicenter of the 1906 San Francisco earthquake.
The fault returns onshore at Bolinas Lagoon just north of Stinson Beach in Marin County, from Fort Ross the northern segment continues overland, forming in part a linear valley through which the Gualala River flows. It goes back offshore at Point Arena, after that, it runs underwater along the coast until it nears Cape Mendocino, where it begins to bend to the west, terminating at the Mendocino Triple Junction. The central segment of the San Andreas fault runs in a direction from Parkfield to Hollister. The southern segment begins near Bombay Beach, box Canyon, near the Salton Sea, contains upturned strata associated with that section of the fault. The fault runs along the base of the San Bernardino Mountains, crosses through the Cajon Pass. These mountains are a result of movement along the San Andreas Fault and are called the Transverse Range. In Palmdale, a portion of the fault is easily examined at a roadcut for the Antelope Valley Freeway, the fault continues northwest alongside the Elizabeth Lake Road to the town of Elizabeth Lake.
As it passes the towns of Gorman, Tejon Pass and Frazier Park and this restraining bend is thought to be where the fault locks up in Southern California, with an earthquake-recurrence interval of roughly 140–160 years. Northwest of Frazier Park, the runs through the Carrizo Plain. The Elkhorn Scarp defines the fault trace along much of its length within the plain, the southern segment, which stretches from Parkfield in Monterey County all the way to the Salton Sea, is capable of an 8. 1-magnitude earthquake. At its closest, this fault passes about 35 miles to the northeast of Los Angeles. Such a large earthquake on this segment would kill thousands of people in Los Angeles, San Bernardino and surrounding areas
Traditional definitions require a topographic map to show both natural and man-made features. A topographic map is published as a map series, made up of two or more map sheets that combine to form the whole map. A contour line is a line connecting places of equal elevation, however, in the vernacular and day to day world, the representation of relief is popularly held to define the genre, such that even small-scale maps showing relief are commonly called topographic. The study or discipline of topography is a broader field of study. Topographic maps are based on topographical surveys, performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms. This is in contrast to older cadastral surveys, which primarily show property, the first multi-sheet topographic map series of an entire country, the Carte géométrique de la France, was completed in 1789. Topographic surveys were prepared by the military to assist in planning for battle, as such, elevation information was of vital importance.
As they evolved, topographic map series became a resource in modern nations in planning infrastructure. Excluding borders, each sheet was 44 cm high and up to 66 cm wide, although the project eventually foundered, it left an indexing system that remains in use. TIGER was developed in the 1980s and used in the 1990, digital elevation models were compiled, initially from topographic maps and stereographic interpretation of aerial photographs and from satellite photography and radar data. Since all these were government projects funded with taxes and not classified for security reasons. Initial applications were mostly professionalized forms such as innovative surveying instruments, by the mid-1990s, increasingly user-friendly resources such as online mapping in two and three dimensions, integration of GPS with mobile phones and automotive navigation systems appeared. As of 2011, the future of standardized, centrally printed topographical maps is left somewhat in doubt, the various features shown on the map are represented by conventional signs or symbols.
For example, colors can be used to indicate a classification of roads and these signs are usually explained in the margin of the map, or on a separately published characteristic sheet. Topographic maps are commonly called contour maps or topo maps. In the United States, where the national series is organized by a strict 7. 5-minute grid. Topographic maps conventionally show topography, or land contours, by means of contour lines, contour lines are curves that connect contiguous points of the same altitude. In other words, every point on the line of 100 m elevation is 100 m above mean sea level
The Mojave Desert is an arid rain-shadow desert and the driest desert in North America. It is located in the southwestern United States, primarily within southeastern California and southern Nevada, very small areas extend into Utah and Arizona. The central part of the desert is sparsely populated, while its peripheries support large communities such as Las Vegas, Palmdale, the Mojave Desert is bordered by the Great Basin Desert to its north and the Sonoran Desert to its south and east. Topographical boundaries include the Tehachapi Mountains to the west, and the San Gabriel Mountains, the mountain boundaries are distinct because they are outlined by the two largest faults in California – the San Andreas and Garlock faults. The Mojave Desert displays typical basin and range topography and it occupies less than 50,000 sq mi, making it the smallest of the North American deserts. The Mojave Desert is often referred to as the desert, in contrast to the low desert. However, the Mojave Desert is generally lower than the Great Basin Desert to the north, the spelling Mojave originates from the Spanish language while the spelling Mohave comes from modern English.
The Mojave Desert receives less than 13 in of rain a year and is generally between 2,000 and 5,000 feet in elevation, zion National Park in Utah lies at the junction of the Mojave, the Great Basin Desert, and the Colorado Plateau. Despite its aridity, the Mojave has long been a center of production, fed by irrigation coming from groundwater. The Mojave is a desert of temperature extremes and two distinct seasons, winter months bring comfortable daytime temperatures, which dip precipitously to around 20 °F on valley floors, and below 0 °F at higher elevations. Storms moving from the Pacific Northwest can bring rain and in places even snow. More often, the shadow created by the Sierra Nevada as well as mountain ranges within the desert such as the Spring Mountains, bring only clouds. By early June, it is rare for another Pacific storm to have a significant impact on the regions weather, summer weather is dominated by heat. Temperatures on valley floors can soar above 120 °F and above 130 °F at the lowest elevations, low humidity, high temperatures, and low pressure, draw in moisture from the Gulf of Mexico creating thunderstorms across the desert southwest known as the North American monsoon.
Autumn is generally pleasant, with one to two Pacific storm systems creating regional rain events, october is one of the driest and sunniest months in the Mojave, and temperatures usually remain between 70 °F and 90 °F on the valley floors. After temperature, wind is the most significant weather phenomenon in the Mojave, during the June Gloom, cooler air can be pushed out into the desert from Southern California. In Santa Ana wind events, hot air from the desert blows out into the Los Angeles basin, wind farms in these areas generate power from these winds. The other major factor in the region is elevation
Lava Beds National Monument
Lava Beds National Monument is located in northeastern California, in Siskiyou and Modoc counties. The Monument lies on the flank of the Medicine Lake Volcano. The region in and around Lava Beds Monument lies at the junction of the Sierra-Klamath, the Monument was established as a United States National Monument on November 21,1925, and includes more than 46,000 acres. Lava Beds National Monument has numerous lava tube caves, with twenty-five having marked entrances and developed trails for public access, the monument offers trails through the high Great Basin xeric shrubland desert landscape and the volcanic field. 1872–1873, this area was the site of the Modoc War, the area of Captain Jacks Stronghold was named in his honor. Volcanic eruptions on the Medicine Lake shield volcano have created a rugged landscape punctuated by these many landforms of volcanism. Cinder cones are formed when magma is under great pressure and it is released in a fountain of lava, blown into the air from a central vent.
The lava cools as it falls, forming cinders that pile up around the vent, when the pressure has been relieved, the rest of the lava flows from the base of the cone. Cinder cones typically only erupt once, the cinder cones of Hippo Butte, Three Sisters, Juniper Butte, and Crescent Butte are all older than the Mammoth and Modoc Crater flows, more than 30, 000–40,000 years old. Eagle Nest Butte and Bearpaw Butte are 114,000 years old, Schonchin Butte cinder cone and the andesitic flow from its base were formed around 62,000 years ago. The flow that formed Valentine Cave erupted 10,850 years ago, an eruption that formed The Castles is younger than the Mammoth Crater flows. Even younger were eruptions from Fleener Chimneys, such as the Devils Homestead flow,10,500 years ago, about 1,110 years ago, plus or minus 60 years, the Callahan flow was produced by an eruption from Cinder Butte. Though Cinder Butte is just outside the boundary of the monument, spatter cones are built out of thicker lava. The lava is thrown out of the vent and builds, layer by layer, Fleener Chimneys and Black Crater are examples of spatter cones.
Roughly ninety percent of the lava in the Lava Beds Monument is basaltic, there are primarily two kinds of basaltic lava flows, pahoehoe and aa. Pahoehoe is smooth, often ropy and is the most common type of lava in Lava Beds, aa is formed when pahoehoe cools and loses some of its gases. Aa is rough and jagged, an excellent example is the Devils Homestead lava flow, most of the rest of the lava in the monument is andesitic. Pumice, a type of lava, is found covering the monument
It is the hottest desert in Mexico. It has an area of 260,000 square kilometers, the western portion of the United States–Mexico border passes through the Sonoran Desert. In phytogeography, the Sonoran Desert is within the Sonoran Floristic Province of the Madrean Region in southwestern North America, the desert contains a variety of unique and endemic plants and animals, such as the saguaro and organ pipe cactus. It is bounded on the west by the Peninsular Ranges, which separate it from the California chaparral and woodlands, to the north in California and northwest Arizona, the Sonoran Desert transitions to the colder-winter, higher-elevation Mojave, Great Basin, and Colorado Plateau deserts. To the east and southeast, the transition to the coniferous Arizona Mountains forests and Sierra Madre. To the south the Sonoran–Sinaloan transition subtropical dry forest is the zone from the Sonoran Desert to the tropical dry forests of the Mexican state of Sinaloa. The deserts sub-regions include the Colorado Desert of southeastern California, many ecologists now consider Shreves Vizcaíno and Magdalena regions, which lie on the western side of the Baja California Peninsula, to be a separate ecoregion, the Baja California Desert.
The Pinacate National Park includes the only active Erg dune region in North America, the nearest city to the Reserva de la Biosfera el Pinacate y Gran Desierto de Altar is Puerto Peñasco in the state of Sonora, Mexico. The Sonoran Desert area southeast of Tucson and near the Mexican border is vital habitat for the population of jaguars living within the United States. Many plants not only survive, but thrive in the conditions of the Sonoran Desert. Many have evolved to have specialized adaptations to the desert climate, the Sonoran Deserts biseasonal rainfall pattern results in more plant species than any other desert in the world. The Sonoran Desert includes plant genera and species from the family, palm family, cactus family, legume family. The Sonoran is the place in the world where the famous saguaro cactus grows in the wild. Cholla, hedgehog, prickly pear, nightblooming cereus, creosote bush and bur sage dominate valley floors. Indigo bush and Mormon tea are other shrubs that may be found, wildflowers of the Sonoran Desert include desert sand verbena, desert sunflower, and evening primroses.
Ascending from the valley up bajadas, various such as velvet mesquite, palo verde, desert ironwood, desert willow. Shrubs found at higher elevations include whitethorn acacia, fairy duster, in the desert subdivisions found on Baja California, cardon cactus, elephant tree, and boojum tree occur. The California fan palm is found in the Colorado Desert section of the Sonoran Desert and it is found at spring-fed oases, such as in Anza Borrego Desert State Park, Joshua Tree National Park, and the Kofa National Wildlife Refuge
Lassen Volcanic National Park
Lassen Volcanic National Park is a United States National Park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world, Lassen Volcanic National Park started as two separate national monuments designated by President Theodore Roosevelt in 1907, Cinder Cone National Monument and Lassen Peak National Monument. The source of heat for volcanism in the Lassen area is subduction off the Northern California coast of the Gorda Plate diving below the North American Plate, the area surrounding Lassen Peak is still active with boiling mud pots, stinking fumaroles, and churning hot springs. Lassen Volcanic National Park is one of the few areas in the world where all four types of volcano can be found, the park is accessible via State Routes SR89 and SR44. SR89 passes north-south through the park, beginning at SR36 to the south, SR89 passes immediately adjacent the base of Lassen Peak. A large lodge with concession facilities was located near the south-west entrance, a new, full-service visitor center was constructed in the same location, and opened to the public in 2008.
Near the old location was located Lassen Ski Area. Native Americans have inhabited the area long before white settlers first saw Lassen. The natives knew that the peak was full of fire and water, White immigrants in the mid-19th century used Lassen Peak as a landmark on their trek to the fertile Sacramento Valley. One of the guides to these immigrants was a Danish blacksmith named Peter Lassen, Lassen Peak was named after him. Nobles Emigrant Trail was cut through the area and passed Cinder Cone. Inconsistent newspaper accounts reported by witnesses from 1850 to 1851 described seeing fire thrown to a terrible height, as late as 1859, a witness reported seeing fire in the sky from a distance, attributing it to an eruption. Early geologists and volcanologists who studied the Cinder Cone concluded the last eruption occurred between 1675 and 1700, after the 1980 eruption of Mount St. Helens, the United States Geological Survey began reassessing the potential risk of other active volcanic areas in the Cascade Range.
Further study of Cinder Cone estimated the last eruption occurred between 1630 and 1670, recent tree-ring analysis has placed the date at 1666. The Lassen area was first protected by being designated as the Lassen Peak Forest Preserve, Lassen Peak and Cinder Cone were declared as U. S. National Monuments in May 1907 by President Theodore Roosevelt. Starting in May 1914 and lasting until 1921, a series of minor to major eruptions occurred on Lassen and these events created a new crater, and released lava and a great deal of ash. Fortunately, because of warnings, no one was killed, because of the eruptive activity, which continued through 1917, and the areas stark volcanic beauty, Lassen Peak, Cinder Cone and the area surrounding were declared a National Park on August 9,1916. The 29-mile Main Park Road was constructed between 1925 and 1931, just 10 years after Lassen Peak erupted, near Lassen Peak the road reaches 8,512 feet, making it the highest road in the Cascade Mountains
Death Valley National Park
Death Valley National Park is a national park in the United States. Straddling the border of California and Nevada, located east of the Sierra Nevada, the park protects the northwest corner of the Mojave Desert and contains a diverse desert environment of salt-flats, sand dunes, valleys and mountains. It is the largest national park in the lower 48 states and has declared an International Biosphere Reserve. Approximately 91% of the park is a wilderness area. It is the hottest and lowest of the parks in the United States. The second-lowest point in the Western Hemisphere is in Badwater Basin, the park is home to many species of plants and animals that have adapted to this harsh desert environment. Some examples include creosote bush, bighorn sheep and the Death Valley pupfish, several short-lived boom towns sprang up during the late 19th and early 20th centuries to mine gold and silver. The only long-term profitable ore to be mined was borax, which was transported out of the valley with twenty-mule teams, the valley became the subject of books, radio programs, television series, and movies.
Tourism blossomed in the 1920s, when resorts were built around Stovepipe Wells, Death Valley National Monument was declared in 1933 and the park was substantially expanded and became a national park in 1994. The natural environment of the area has been shaped largely by its geology, the valley itself is actually a graben. The oldest rocks are metamorphosed and at least 1.7 billion years old. Ancient, shallow seas deposited marine sediments until rifting opened the Pacific Ocean, additional sedimentation occurred until a subduction zone formed off the coast. This uplifted the region out of the sea and created a line of volcanoes, the crust started to pull apart, creating the current Basin and Range landform. Valleys filled with sediment and, during the wet times of glacial periods, with lakes, in 2013, Death Valley National Park was designated as a dark sky park by the International Dark-Sky Association. There are two valleys in the park, Death Valley and Panamint Valley. Both of these valleys were formed within the last few million years, the result of this shearing action is additional extension in the central part of Death Valley which causes a slight widening and more subsidence there.
Uplift of surrounding mountain ranges and subsidence of the floor are both occurring. The uplift on the Black Mountains is so fast that the fans there are small
National Park Service
It was created on August 25,1916, by Congress through the National Park Service Organic Act and is an agency of the United States Department of the Interior. As of 2014, the NPS employs 21,651 employees who oversee 417 units, the National Park Service celebrated its centennial in 2016. National parks and national monuments in the United States were originally individually managed under the auspices of the Department of the Interior, the movement for an independent agency to oversee these federal lands was spearheaded by business magnate and conservationist Stephen Mather, as well as J. Horace McFarland. With the help of journalist Robert Sterling Yard, Mather ran a publicity campaign for the Department of the Interior and they wrote numerous articles that praised the scenic and historic qualities of the parks and their possibilities for educational and recreational benefits. This campaign resulted in the creation of a National Park Service, Mather became the first director of the newly formed NPS.
On March 3,1933, President Herbert Hoover signed the Reorganization Act of 1933, the act would allow the President to reorganize the executive branch of the United States government. It wasnt until that summer when the new President, Franklin D. Roosevelt, President Roosevelt agreed and issued two Executive orders to make it happen. In 1951, Conrad Wirth became director of the National Park Service, the demand for parks after the end of the World War II had left the parks overburdened with demands that could not be met. In 1952, with the support of President Dwight D. Eisenhower, he began Mission 66, New parks were added to preserve unique resources and existing park facilities were upgraded and expanded. In 1966, as the Park Service turned 50 years old, emphasis began to turn from just saving great and wonderful scenery, Director George Hartzog began the process with the creation of the National Lakeshores and National Recreation Areas. Since its inception in 1916, the National Park Service has managed each of the United States national parks, Yellowstone National Park was the first national park in the United States.
In 1872, there was no government to manage it. Yosemite National Park began as a park, the land for the park was donated by the federal government to the state of California in 1864 for perpetual conservation. Yosemite was returned to federal ownership, at first, each national park was managed independently, with varying degrees of success. In Yellowstone, the staff was replaced by the U. S. Army in 1886. Due to the irregularities in managing these national treasures, Stephen Mather petitioned the government to improve the situation. In response, Secretary of the Interior Franklin K. Lane challenged him to lobby for creating a new agency, Mather was successful with the ratification of the National Park Service Organic Act in 1916. Later, the agency was given authority over other protected areas, the National Park System includes all properties managed by the National Park Service
California is the most populous state in the United States and the third most extensive by area. Located on the western coast of the U. S, California is bordered by the other U. S. states of Oregon and Arizona and shares an international border with the Mexican state of Baja California. Los Angeles is Californias most populous city, and the second largest after New York City. The Los Angeles Area and the San Francisco Bay Area are the nations second- and fifth-most populous urban regions, California has the nations most populous county, Los Angeles County, and its largest county by area, San Bernardino County. The Central Valley, an agricultural area, dominates the states center. What is now California was first settled by various Native American 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 war for independence.
The western portion of Alta California was organized as the State of California, 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. If it were a country, California would be the 6th largest economy in the world, fifty-eight percent of the states economy is centered on finance, real estate services and professional, scientific and technical business services. Although it accounts for only 1.5 percent of the states economy, the story of Calafia is recorded in a 1510 work The Adventures of Esplandián, written as a sequel to Amadis de Gaula by Spanish adventure writer Garci Rodríguez de Montalvo. The kingdom of Queen Calafia, according to Montalvo, was said to be a land inhabited by griffins and other strange beasts. This conventional wisdom that California was an island, with maps drawn to reflect this belief, shortened forms of the states name include CA, Cal. Calif. and US-CA.
Settled by successive waves of arrivals during the last 10,000 years, 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 organization with bands, villages. Trade and military alliances fostered many social and economic relationships among the diverse groups, the first European effort to explore the coast as far north as the Russian River was a Spanish sailing expedition, led by Portuguese captain Juan Rodríguez Cabrillo, in 1542. Some 37 years English explorer Francis Drake explored and claimed a portion of the California coast in 1579. Spanish traders made unintended visits with the Manila galleons on their trips from the Philippines beginning in 1565
Fort Point, San Francisco
Fort Point is a masonry seacoast fortification located at the southern side of the Golden Gate at the entrance to San Francisco Bay. This fort was completed just before the American Civil War by the United States Army, the fort is now protected as Fort Point National Historic Site, a United States National Historic Site administered by the National Park Service as a unit of the Golden Gate National Recreation Area. In 1769 Spain occupied the San Francisco area and by 1776 had established the areas first European settlement, with a mission and a presidio. To protect against encroachment by the British and Russians, Spain fortified the high white cliff at the narrowest part of the bays entrance, the Castillo de San Joaquin, built in 1794, was an adobe structure housing nine to thirteen cannons. Mexico won independence from Spain in 1821, gaining control of the region and the fort, following the United States victory in 1848, California was annexed by the U. S. and became a state in 1850. The gold rush of 1849 had caused rapid settlement of the area, military officials soon recommended a series of fortifications to secure San Francisco Bay.
Coastal defenses were built at Alcatraz Island, Fort Mason, the U. S. Army Corps of Engineers began work on Fort Point in 1853. Plans specified that the lowest tier of artillery be as close as possible to water level so cannonballs could ricochet across the surface to hit enemy ships at the water-line. Workers blasted the 90-foot cliff down to 15 feet above sea level, the structure featured seven-foot-thick walls and multi-tiered casemated construction typical of Third System forts. It was sited to defend the maximum amount of harbor area, while there were more than 30 such forts on the East Coast, Fort Point was the only one on the West Coast. In 1854 Inspector General Joseph K. Mansfield declared this point as the key to the whole Pacific Coast. a crew of 200, many unemployed miners, labored for eight years on the fort. In 1861, with war looming, the army mounted the forts first cannon, colonel Albert Sidney Johnston, commander of the Department of the Pacific, prepared Bay Area defenses and ordered in the first troops to the fort.
Kentucky-born Johnston resigned his commission to join the Confederate Army, throughout the Civil War, artillerymen at Fort Point stood guard for an enemy that never came. Troops soon moved out of Fort Point, and it was never again occupied by the army. The fort was important enough to receive protection from the elements. In 1869 a granite seawall was completed, the following year, some of the forts cannon were moved to Battery East on the bluffs nearby, where they were more protected. In 1882 Fort Point was officially named Fort Winfield Scott after the hero from the war against Mexico. The name never caught on and was applied to an artillery post at the Presidio
Muir Woods National Monument
Muir Woods National Monument is a unit of the National Park Service on Mount Tamalpais near the Pacific coast, in southwestern Marin County, California. It is part of the Golden Gate National Recreation Area, and is 12 miles north of San Francisco and it protects 554 acres, of which 240 acres are old growth coast redwood forests, one of a few such stands remaining in the San Francisco Bay Area. The Muir Woods National Monument is an old-growth coastal redwood forest, due to its proximity to the Pacific Ocean, the forest is regularly shrouded in a coastal marine layer fog, contributing to a wet environment that encourages vigorous plant growth. The fog is vital for the growth of the redwoods as they use moisture from the fog during droughty seasons, the monument is cool and moist year round with average daytime temperatures between 40 and 70 degrees Fahrenheit. Rainfall is heavy during the winter and summers are almost completely dry with the exception of fog drip caused by the fog passing through the trees.
Annual precipitation in the ranges from 39.4 inches in the lower valley to 47.2 inches higher up in the mountain slopes. The redwoods grow on brown humus-rich loam which may be gravelly and this soil has been assigned to the Centissima series, which is always found on sloping ground. It is well drained, moderately deep, and slightly to moderately acidic and it has developed from a mélange in the Franciscan Formation. More open areas of the park have shallow gravelly loam of the Barnabe series, one hundred and fifty million years ago ancestors of redwood and sequoia trees grew throughout the United States. Today, the Sequoia sempervirens can be only in a narrow, cool coastal belt from Monterey, California. Before the logging industry came to California, there were an estimated 2 million acres of old growth forest containing redwoods growing in a strip along the coast. By the early 20th century, most of these forests had been cut down, just north of the San Francisco Bay, one valley named Redwood Canyon remained uncut, mainly due to its relative inaccessibility.
He and his wife, Elizabeth Thacher Kent, purchased 611 acres of land from the Tamalpais Land and Water Company for $45,000 with the goal of protecting the redwoods and the mountain above them. In 1907, a company in nearby Sausalito planned to dam Redwood Creek. When Kent objected to the plan, the company threatened to use eminent domain. Kent sidestepped the water companys plot by donating 295 acres of the redwood forest to the federal government, on January 9,1908, President Theodore Roosevelt declared the land a National Monument, the first to be created from land donated by a private individual. President Roosevelt agreed, writing back, MY DEAR MR, responding to some photographs of Muir Woods that Mr. Kent had sent him, Those are awfully good photos. Kent and Muir had become friends over shared views of wilderness preservation, in December 1928, the Kent Memorial was erected at the Kent Tree in Fern Canyon
Chuckwallas are large lizards found primarily in arid regions of the southwestern United States and northern Mexico. Some are found on coastal islands, the five species of chuckwallas are all placed within the genus Sauromalus, they are part of the iguanid family, Iguanidae. The generic name, Sauromalus, is a combination of two Ancient Greek words, σαῦρος meaning lizard and ομαλυς meaning flat, the common name chuckwalla derives from the Shoshone word tcaxxwal or Cahuilla čaxwal, transcribed by Spaniards as chacahuala. Chuckwallas are stocky, wide-bodied lizards with flattened midsections and prominent bellies and their tails are thick, tapering to a blunt tip. Loose folds of skin characterize the neck and sides of their bodies, the common chuckwalla measures 15 3/4 inches long, whereas insular species such as the San Esteban chuckwalla of San Esteban Island can measure as long as 30 in. The genus Sauromalus has a distribution in biomes of the Sonoran. The peninsular chuckwalla is found on the portion of the southern half of the Baja California Peninsula.
The other species are island-dwelling, so have more restricted distributions. The Angel Island chuckwalla is found on Isla Ángel de la Guarda, chuckwallas prefer lava flows and rocky areas typically vegetated by creosote bush and other such drought-tolerant scrub. The lizards may be found at elevations up to 4,500 ft. Primarily herbivorous, chuckwallas feed on leaves, the lizards are said to prefer yellow flowers, such as those of the brittlebush. Harmless to humans, these lizards are known to run from potential threats, when disturbed, a chuckwalla wedges itself into a tight rock crevice and inflates its lungs to entrench itself. Males are seasonally and conditionally territorial, an abundance of resources tends to create a hierarchy based on size, chuckwallas use a combination of color and physical displays, namely push-ups, head-hobbing, and gaping of the mouth, to communicate and defend their territory. Chuckwallas are diurnal animals and as they are ectothermic, spend much of their mornings and these lizards are well adapted to desert conditions, they are active at temperatures up to 102°F.
Juveniles emerge first, adults, as temperatures reach around 90°F, chuckwallas hibernate during cooler months and emerge in February. Mating occurs from April to July, with five to 16 eggs laid between June and August, the eggs hatch in late September. Chuckwallas may live for 25 years or more, the Comca’ac considered the Angel Island species of chuckwalla an important food item. They are believed to have translocated the lizards to most of the islands in Bahia de los Angeles for use as a source in times of need. ARKive - images and movies of the San Esteban Island chuckwalla www. chuckwalla-reptiles-tirol. at https, //www. facebook. com/groups/555917997826565/