Devils Postpile National Monument
Devils Postpile National Monument is located near Mammoth Mountain in eastern California. The national monument protects Devils Postpile, a rock formation of columnar basalt. In addition, the John Muir Trail and Pacific Crest Trail merge into one trail as they pass through the monument, excluding a small developed area containing the monument headquarters, visitor center and a campground, the National Monument lies within the borders of the Ansel Adams Wilderness. The monument was once part of Yosemite National Park, but discovery of gold in 1905 near Mammoth Lakes prompted a change that left the Postpile on adjacent public land. Later, a proposal to build a dam called for blasting the Postpile into the river. Influential Californians, including John Muir, persuaded the government to stop the demolition and, in 1911. The flora and fauna at Devils Postpile are typical of the Sierra Nevada, dark-eyed juncos and white-crowned sparrows are common in the summer. The name Devils Postpile refers to a cliff of columnar basalt.
Radiometric dating indicates the formation was created by a flow at some time less than 100,000 years ago. Estimates of the thickness range from 400 feet to 600 feet. The lava that now makes up the Postpile was near the bottom of this mass, because of its great thickness, much of the mass of pooled lava cooled slowly and evenly, which is why the columns are so long and so symmetrical. Columnar jointing occurs when certain types of contract while cooling. A glacier removed much of this mass of rock and left a surface on top of the columns with very noticeable glacial striations. The Postpiles columns average 2 feet in diameter, the largest being 3.5 feet, together they look like tall posts stacked in a pile, hence the features name. If the lava had cooled perfectly evenly, all of the columns would be expected to be hexagonal, but some of the columns have different polygonal cross-sections due to variations in cooling. A survey of 400 of the Postpiles columns found that 44. 5% were 6-sided,37. 5% 5-sided,9. 5% 4-sided,8.
0% 7-sided, compared with other examples of columnar jointing, the Postpile has more hexagonal columns. Another feature that places the Postpile in a category is the lack of horizontal jointing. Several stones from the Devils Postpile can be seen at the entrance to the United States Geological Survey headquarters lot in Reston, although the basaltic columns are impressive, they are not unique
Channel Islands National Park
Channel Islands National Park is a United States national park that consists of five of the eight Channel Islands off the coast of the U. S. state of California, in the Pacific Ocean. Although the islands are close to the shore of densely populated Southern California, the park covers 249,561 acres of which 79,019 acres are owned by the federal government. The Nature Conservancy owns and manages 76% of Santa Cruz Island, Channel Islands National Park is home to a wide variety of significant natural and cultural resources. It was designated a U. S. National Monument on April 26,1938, and it was promoted to a National Park on March 5,1980. Channel Islands National Marine Sanctuary encompasses the waters six nautical miles around Channel Islands National Park, the Channel Islands were originally discovered in 1542 by the explorer Juan Rodríguez Cabrillo. In 1938 the Santa Barbara and Anacapa islands were designated a national monument, San Miguel, Santa Rosa and Santa Cruz islands were combined with the monument in 1980 to form modern-day Channel Islands National Park.
On January 28,1969 an oil rig belonging to Union Oil experienced a blow-out 6 miles off the coast of California, the resulting spill was, at the time, the largest oil spill to occur in United States territorial waters. Following the spill, tides carried the oil onto the beaches of the Anacapa, San Miguel, Santa Rosa and this spill had a large impact on native wildlife of the Channel Islands. Much of the seabird population was affected, with over an estimated 3,600 avians killed. Meanwhile, seals and other sea life died and washed ashore on both the islands and the mainland and this spill is the third largest oil spill in the United States, only surpassed by the Deepwater Horizon and the Exxon Valdez oil spills. It resulted in a 34,000 acres expansion of the Department of the Interior buffer zone in the channel, the islands within the park extend along the Southern California coast from Point Conception near Santa Barbara to San Pedro, a neighborhood of Los Angeles. Park headquarters and the Robert J.
Lagomarsino Visitor Center are located in the city of Ventura, only three mammals are endemic to the islands, one of which is the deer mouse which is known to carry the sin nombre hantavirus. The spotted skunk and Channel Islands fox are endemic, the island fence lizard is endemic to the Channel Islands. One hundred and forty-five of these species are unique to the islands, Marine life ranges from microscopic plankton to the endangered blue whale, the largest animal on earth. Archeological and cultural resources span a period of more than 10,000 years, the average annual visitation to the parks mainland visitor center was around 300,000 in the period from 2007 to 2016, with 364,807 visiting in 2016. The visitor center is located in the Ventura Harbor Village, the visitor center contains several exhibits that provide information regarding all five islands, native vegetation, marine life and cultural history. Also, visitors can enjoy a film, free of charge. The visitor center is open day, except Thanksgiving and Christmas, from 8, 30AM–5
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
In physical geography, a dune is a hill of loose sand built by wind or the flow of water. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water, most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter slip face in the lee of the wind. The valley or trough between dunes is called a slack, a dune field is an area covered by extensive sand dunes. Dunes occur, for example, in deserts and along some coasts. Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach, in most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, Dunes can form under the action of water flow, and on sand or gravel beds of rivers and the sea-bed. The modern word dune came into English from French c,1790, which in turn came from Middle Dutch dūne.
Crescent-shaped mounds are generally wider than they are long, the slipfaces are on the concave sides of the dunes. These dunes form under winds that blow consistently from one direction, some types of crescentic dunes move more quickly over desert surfaces than any other type of dune. A group of dunes moved more than 100 metres per year between 1954 and 1959 in Chinas Ningxia Province, and similar speeds have been recorded in the Western Desert of Egypt. The largest crescentic dunes on Earth, with mean crest-to-crest widths of more than three kilometres, are in Chinas Taklamakan Desert. They may be composed of clay, sand, or gypsum, eroded from the floor or shore, transported up the concave side of the dune. Examples in Australia are up to 6.5 km long,1 km wide and they occur in southern and West Africa, and in parts of the western United States, especially Texas. Straight or slightly sinuous sand ridges typically much longer than they are wide are known as linear dunes and they may be more than 160 kilometres long.
Some linear dunes merge to form Y-shaped compound dunes, many form in bidirectional wind regimes. The long axes of these dunes extend in the resultant direction of sand movement, linear loess hills known as pahas are superficially similar. These hills appear to have formed during the last ice age under permafrost conditions dominated by sparse tundra vegetation. Radially symmetrical, star dunes are pyramidal sand mounds with slipfaces on three or more arms that radiate from the center of the mound
Joshua Tree National Park
Joshua Tree National Park is located in southeastern California. Declared a U. S. National Park in 1994 when the U. S. Congress passed the California Desert Protection Act and it is named for the Joshua trees native to the park. It covers a area of 790,636 acres —an area slightly larger than the state of Rhode Island. A large part of the park, some 429,690 acres, is a wilderness area. The Little San Bernardino Mountains run through the southwest edge of the park, in 1950, the size of the park was reduced by about 265,000 acres to exclude some mining property. The park was elevated to a National Park on 31 October 1994 by the Desert Protection Act, the higher and cooler Mojave Desert is the special habitat of Yucca brevifolia, the Joshua tree for which the park is named. It occurs in patterns from dense forests to distantly spaced specimens, in addition to Joshua tree forests, the western part of the park includes some of the most interesting geologic displays found in Californias deserts. The dominant geologic features of landscape are hills of bare rock.
These hills are popular amongst rock climbing and scrambling enthusiasts, the flatland between these hills is sparsely forested with Joshua trees. Together with the piles and Skull Rock, the trees make the landscape otherworldly. Temperatures are most comfortable in the spring and fall, with an average high/low of 85 and 50 °F respectively, winter brings cooler days, around 60 °F, and freezing nights. It occasionally snows at higher elevations, summers are hot, over 100 °F during the day and not cooling much below 75 °F until the early hours of the morning. Joshua trees dominate the open spaces of the park, but in among the outcroppings are piñon pine, California juniper, Quercus turbinella, Quercus john-tuckeri. These communities are under stress, however, as the climate was wetter until the 1930s, with the same hot. These cycles were nothing new, but the vegetation did not prosper when wetter cycles returned. The difference may have been human development, cattle grazing took out some of the natural cover and made it less resistant to the changes.
But the bigger problem seems to be invasive species, such as cheatgrass, in drier times, they die back, but do not quickly decompose. This makes wildfires hotter and more destructive, which some of the trees that would have otherwise survived
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
Arnold Alois Schwarzenegger is an Austrian-American actor, businessman, author, activist and former professional bodybuilder. He served two terms as the 38th Governor of California from 2003 until 2011, Schwarzenegger began weight training at the age of 15. He won the Mr. Universe title at age 20 and went on to win the Mr. Olympia contest seven times, Schwarzenegger has remained a prominent presence in bodybuilding and has written many books and articles on the sport. He is widely considered to be among the greatest bodybuilders of all time as well as bodybuildings biggest icon, Schwarzenegger gained worldwide fame as a Hollywood action film icon. His breakthrough film was the sword-and-sorcery epic Conan the Barbarian in 1982, in 1984, Schwarzenegger appeared in James Camerons science-fiction thriller film The Terminator, which was a massive critical and box-office success. Schwarzenegger subsequently reprised the Terminator character in the installments in 1991,2003. He appeared in a number of films, such as Commando, The Running Man, Twins, Total Recall, Kindergarten Cop.
In 2015, it was announced Schwarzenegger would replace Donald Trump as the host of The Celebrity Apprentice and he was nicknamed the Austrian Oak in his bodybuilding days, Arnie during his acting career, and The Governator during his political career. As a Republican, he was first elected on October 7,2003, Schwarzenegger was sworn in on November 17, to serve the remainder of Daviss term. Schwarzenegger was sworn in for his term on January 5,2007. In 2011, Schwarzenegger completed his term as governor. Schwarzenegger was born in Thal and christened Arnold Alois and his parents were Gustav Schwarzenegger and Aurelia Schwarzenegger. He married Aurelia on October 20,1945, he was 38, according to Schwarzenegger, both of his parents were very strict, Back in Austria it was a very different world. If we did something bad or we disobeyed our parents, the rod was not spared, Schwarzenegger grew up in a Roman Catholic family who attended Mass every Sunday. Gustav had a preference for his son, over Arnold.
His favoritism was strong and blatant, which stemmed from unfounded suspicion that Arnold was not his biological child, Schwarzenegger has said his father had no patience for listening or understanding your problems. He had a relationship with his mother and kept in touch with her until her death. Gustavs background received wide press attention during the 2003 California recall campaign, at school, Schwarzenegger was reportedly academically average, but stood out for his cheerful, good-humored, and exuberant character
Point Reyes National Seashore
Point Reyes National Seashore is a 71, 028-acre park preserve located on the Point Reyes Peninsula in Marin County, California. As a national seashore, it is maintained by the US National Park Service as an important nature preserve, some existing agricultural uses are allowed to continue within the park. All of the beaches were listed as the cleanest in the state in 2010. The fact that the peninsula is on a different tectonic plate than the east shore of Tomales Bay produces a difference in soils and therefore to some extent a noticeable difference in vegetation. The even smaller town of Olema, about 3 miles south of Point Reyes Station, serves as the gateway to the Seashore and its visitor center, the peninsula includes wild coastal beaches and headlands and uplands. The Seashore administers the parts of the Golden Gate National Recreation area, such as the Olema Valley, the northernmost part of the peninsula is maintained as a reserve for Tule Elk, which are readily seen there. The preserve is very rich in raptors and shorebirds.
The Point Reyes Lighthouse attracts whale-watchers looking for the Gray Whale migrating south in mid-January, the Point Reyes Lifeboat Station is a National Historic Landmark. It is the last remaining example of a rail launched lifeboat station that was common on the Pacific coast and this encompasses 5,965 acres along the coast of Drakes Bay. Kule Loklo, a recreated Coast Miwok village, is a walk from the visitor center. The Point Reyes National Seashore attracts 2.5 million visitors annually, hostelling International USA maintains a 45-bed youth hostel at the Seashore. Point Reyes National Seashore Association, formed in 1964, collaborates with the Seashore on maintenance, like underwater parks, these marine protected areas help conserve ocean wildlife and marine ecosystems. A large shellfish farm raising Japanese oysters, Crassostrea gigas, was located in Drakes Estero until, under court order, Court appeals to keep the operation in place were dropped in December,2014. The farm was purchased by the National Park Service in 1972, a federal law enacted in 2009 authorized, but did not require, Interior Secretary Ken Salazar to renew the permit.
The NPS and conservation groups viewed the farm as an inappropriate and environmentally-insensitive use of the estero, the farms supporters argued that it was not ecologically harmful and was important to the local economy. Salazar visited the farm the previous week and phoned the farms owner to give him the news. The oyster farm closure was challenged in U. S. District Court on January 25,2013, the challenge was rejected by a federal court judge, who ruled that the law gave Salazar unfettered discretion to approve or deny a renewal of the permit. The California Coastal Commission voted on February 7,2013 to unanimously approve cease and desist, an attempt to have the appeals court rehear the case was rejected on January 14,2014 and a petition to the United States Supreme Court was denied on June 30,2014
San Luis Obispo County, California
San Luis Obispo County, officially the County of San Luis Obispo, is a county located in the U. S. state of California. As of the 2010 census, the population was 269,637, the county seat is San Luis Obispo. San Luis Obispo County comprises the San Luis Obispo-Paso Robles-Arroyo Grande, the county is located along the Pacific Ocean in Central California, between Los Angeles and the San Francisco Bay Area. Father Junipero Serra founded the Mission San Luis Obispo de Tolosa in 1772, the mainstays of the economy are California Polytechnic State University with its almost 20,000 students and agriculture. San Luis Obispo County is the third largest producer of wine in California, surpassed only by Sonoma, wine grapes are the second largest agricultural crop in the county, and the wine production they support creates a direct economic impact and a growing wine country vacation industry. The town of San Simeon is located at the foot of the ridge where newspaper publisher William Randolph Hearst built the famed Hearst Castle, other coastal towns include Cambria, Morro Bay, and Los Osos -Baywood Park.
These cities and villages are located northwest of San Luis Obispo city, and Avila Beach, just south of the Five Cities, borders northern Santa Barbara County. Inland, the cities of Paso Robles and Atascadero lie along the Salinas River, San Luis Obispo lies south of Atascadero and north of the Five Cities region. Important settlements existed, for example, in coastal areas such as Morro Bay. Mission San Luis Obispo de Tolosa was founded on September 1,1772 in the area that is now the city of San Luis Obispo, the namesake of the mission and county is Saint Louis of Toulouse, the young bishop of Toulouse in 1297. San Luis Obispo County was one of the counties of California. The Salinas River Valley, a region that figures strongly in several Steinbeck novels, the remote California Valley near Soda Lake is the region most untouched by modernity. Travels through this area and the hills east of highway 101 during wildflower season are very beautiful and can be incorporated with wine tasting at local vineyards.
According to the U. S. Census Bureau, the county has an area of 3,616 square miles. Hispanic or Latino of any race were 55,973 persons,17. 7% of San Luis Obispo County is Mexican,0. 3% Puerto Rican, and 0. 2% Salvadoran. As of the census of 2000, there were 246,681 residents,92,739 households, the population density was 75 people per square mile. There were 102,275 housing units at a density of 31 per square mile. The racial makeup of the county was 84. 6% White,2. 0% Black or African American,1. 0% Native American,2. 7% Asian,0. 1% Pacific Islander,6. 2% from other races, and 3. 4% from two or more races
Trione-Annadel State Park
Trione-Annadel State Park is a state park of California in the United States. It is situated at the edge of Sonoma Valley and is adjacent to Spring Lake Regional Park in Santa Rosa. It offers many activities within its 5, 092-acre property. These lands were occupied by the Wappo and Pomo people in times, who would have primarily inhabited the riparian zones. Annadel includes what some consider the best example of undisturbed northern oak woodlands in existence. Visitors can enjoy the parks wildlife and scenery during any time of the year but are perhaps most rewarded from April through June when most wildflowers are in bloom. Plant communities include California oak woodland, riparian woodland, Douglas fir forest, grassland, the dominant plant community is the oak woodland, which has a canopy of coast live oak, Garry oak, black oak, Pacific madrone, bigleaf maple, and California laurel. Canyon live oak occurs in swales and creeks, in the oak woodlands, the dominant understory plants are native bunchgrasses, wild blackberry, coyote brush, and western poison-oak.
The latter covers nearly one quarter of the understory in the park, Douglas fir occurs in some of the steeper, cooler riparian zones and on north-facing slopes. Common animals in Annadel include black-tailed deer, western gray squirrel, skunk and mountain lion are occasionally observed. There are many species, including the California scrub jay, Stellers jay, acorn woodpecker, black phoebe. In moist areas, amphibians such as the rough-skinned newt can be found, the southern reaches of Annadel are drained by Yulupa Creek and other tributaries of Sonoma Creek, while the northern flanks are part of the Santa Rosa Creek watershed. Eastern slopes are drained by Yulupa and Sonoma Creeks, while the slopes are part of the Spring Creek watershed. Many of Annadels streams are dry in the summer, because rainfall is highly seasonal, Ledson Marsh, which drains into Yulupa Creek, retains some smaller pools of water throughout most of the year. The highest elevation in the park is the top of Bennett Mountain,1,887 feet.
The entirety of Annadel was below the floor as recently as twelve million years ago, around which time massive uplift. Elevations in Annadel range from about 360 to 1,880 feet above sea level, slopes within Annadel commonly range from 15 to 30 percent, but it is not uncommon to encounter slopes up to 70 percent on steep slopes above drainages which are covered in douglas fir forest. Typical soil depths are 35 to 50 centimetres, much of the soil type in the Yulupa Creek riparian zone consists of Laniger loam, with rhyolite outcrops, another relic of the igneous history
San Francisco Maritime National Historical Park
The San Francisco Maritime National Historical Park is located in San Francisco, United States. The park includes a fleet of vessels, a visitor center, a maritime museum. The park is referred to as the San Francisco Maritime Museum. Todays San Francisco Maritime National Historical Park was authorized in 1988, the park incorporates the Aquatic Park Historic District, bounded by Van Ness Avenue, Polk Street, and Hyde Street. The historic fleet of the San Francisco Maritime National Historical Park is moored at the parks Hyde Street Pier, the fleet consists of the following major vessels, Balclutha, an 1886 built square rigged sailing ship. Eureka, an 1890 built steam ferryboat, alma, an 1891 built scow schooner. Hercules, a 1907 built steam tug, eppleton Hall, a 1914 built paddlewheel tug. The fleet includes one hundred small craft. The Visitor Center is housed in the parks 1909 waterfront warehouse, located at the corner of Hyde, the City of San Francisco declared the four-story brick structure an historic landmark in 1974, and the building was listed on the National Register of Historic Places in 1975.
Inside, exhibits tell the story of San Francisco’s colorful and diverse maritime heritage, the visitor center contains a theater and a ranger-staffed information desk. The building was built by the WPA as a public bathhouse. The architects were William Mooser Jr. and William Mooser III, the third-floor gallery is used for visiting exhibitions and in 2005 exhibited Sparks, an exhibition of shipboard radio and radioteletype technology. The Maritime Museum has re-opened after a series of renovations, the Maritime Research Center is the premier resource for San Francisco and Pacific Coast maritime history. Originating in 1939, the collections have become the largest maritime collection on the West Coast, one of these is the San Francisco Maritime National Park Association. The Visitors Center, Hyde Street Pier and Maritime Museum are all situated adjacent to the foot of Hyde Street, the park headquarters and Maritime Research Center are located in Fort Mason, some 10 minutes walk to the west of the other sites.
Opening times and fees for the sites can be found on the parks website. Aquatic Park is a place for open water swimming, both for recreation and training. The South End Rowing Club and Dolphin Club are located in Aquatic Park, WPA murals and sculpture at Aquatic Park — The New Deal Art Registry
Angel Island (California)
Angel Island is an island in San Francisco Bay offering expansive 360° views of the San Francisco skyline, the Marin County Headlands and Mount Tamalpais. The entire island is included within Angel Island State Park and is administered by California State Parks, Angel Island is the second largest island in area of the San Francisco Bay. The island is so large that on a day and Napa can be seen from the north side of the island. The highest point on the island, almost exactly at its center, is Mount Caroline Livermore at a height of 788 feet, the island is separated from the mainland of Marin County by Raccoon Strait, the depth of the water approximately 90 feet. The United States Census Bureau reported an area of 3.107 km². Until about ten years ago, Angel Island was connected to the mainland. From about two years ago the island was a fishing and hunting site for Coast Miwok Native Americans. Similar evidence of Native American settlement is found on the mainland of the Tiburon Peninsula upon Ring Mountain.
In 1775, the Spanish naval vessel San Carlos made the first European entry to the San Francisco Bay under the command of Juan de Ayala, Ayala anchored off Angel Island, and gave it its modern name, the bay where he anchored is now known as Ayala Cove. In his book Two Years Before the Mast, published in 1840, Richard Henry Dana, like much of the California coast, Angel Island was subsequently used for cattle ranching. In 1863, during the American Civil War, the U. S. Army was concerned about Confederate naval raiders attacking San Francisco and it decided to construct artillery batteries on Angel Island, first at Stuart Point and Point Knox. Col. René Edward De Russy was the Chief Engineer, James Terry Gardiner was the engineer tasked with designing and supervising the work. The Army established a camp on the island, and it became an infantry garrison during the US campaigns against Native American peoples in the West. In the 19th century, the designated the entire island as Fort McDowell and developed further facilities there.
A quarantine station was opened in Ayala Cove in 1891, during the Spanish–American War the island served as a discharge depot for returning troops. It continued to serve as a transit station throughout the first half of the 20th century, at the end of World War I the disembarkation center was commanded by William P. Burnham, who had commanded the 82nd Division in France during the war. In 1938, hearings concerning charges of membership in a political party against labor leader Harry Bridges were held on Angel Island before Dean James Landis of Harvard Law School. After eleven weeks of testimony that filled nearly 8,500 pages, the decision was accepted by the United States Department of Labor and Bridges was freed