Coastal sage scrub
Coastal sage scrub known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is within the California chaparral and woodlands ecoregion, of the Mediterranean forests and scrub biome. Plant communityCoastal sage scrub is characterized by low-growing aromatic, drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the coastal lowlands; the community is sometimes called "soft chaparral" due to the predominance of soft, drought-deciduous leaves in contrast to the hard, waxy-cuticled leaves on sclerophyllous plants of California's chaparral communities. FloraCharacteristic shrubs and subshrubs include: California sagebrush Black sage White sage California buckwheat Coast brittle-bush Golden yarrow Larger shrubs include: Toyon Lemonade berry Herbaceous plants, in some locales and succulents, are part of the flora. Hesperoyucca whipplei, colloquially known as Chaparral Yucca, is commonplace throughout the climate zone.
The coastal sage scrub plant community is divided into three geographical subtypes — northern coastal scrub, southern coastal scrub, maritime succulent scrub. The coastal scrub communities are divided into three regions: Northern Coastal Scrub and Coastal Prairie, which lies in San Luis Obispo to Oregon. Coastal Sage scrub, which lies in San Diego to Monterey. Maritime Succulent Scrub, which can be found in the San Diego County to Baja California; the Northern Coastal Scrub consists of prairie, terraces with deep alluvial soils, scrub, found on steeper slopes and ravine areas. Evergreen shrubs and subshrubs, which are soft leaves, they are found in semi-open with multiple layers. Some examples of the plant species that can be found are Bush monkeyflower, Poison oak, Coffee berry, Golden yarrow. California sagebrush can be found in Coastal Sage Scrub community in Orange County; some other plant species that can be found is Giant coreopsis, Black sage, California buckwheat, White sage. Plant species that can be found in Maritime Succulent Scrub is Coast prickly pear, Coast barrel cactus, Cliff spurge, Bush rue, Dudleya spp.
Northern coastal scrub occurs along the Pacific Coast from the northern San Francisco Bay Area northwards to southern Oregon. It forms a landscape mosaic with the California coastal prairie plant community; the predominant plants are low evergreen herbs. Characteristic shrubs include coyote brush, yerba santa, coast silk-tassel and yellow bush lupine. Herbaceous species include western blue-eyed grass, Douglas iris, grasses. Southern coastal scrub is found along the maritime Central Coast region, the terraces and mountains with coastal climate influence in Southern California, its distribution extends from the southwestern San Francisco Bay Area in the north, through Big Sur, Vandenberg Air Force Base, the Oxnard Plain, the Los Angeles Basin, most of Orange County, parts of Riverside County, coastal San Diego County, the northwestern region of Baja California state in Mexico, including the areas around Tijuana and Ensenada. Southern CaliforniaThe metropolitan areas of Los Angeles, San Diego, Tijuana are located in the southern coastal scrublands, most of the scrublands have been lost to urbanization and agriculture.
The plants of this community prefer the mild maritime climates found along Southern California's coastline. World Wildlife Fund estimates that only 15 percent of the coastal sage scrublands remain undeveloped; some of the remaining southern coastal scrub in Los Angeles County can be found in dunes under the takeoff path at Los Angeles International Airport—LAX, in the coastal Santa Monica Mountains National Recreation Area, at the Robert J. Bernard Field Station at the Claremont Colleges. In San Diego County, the Camp Pendleton Marine Corps Base protects larger areas, the Marine Corps Air Station Miramar has vernal pools and the endemic mint Pogogyne abramsii. One of the largest remaining areas of inland coastal sage scrub is found in the Temescal Mountains of Riverside County. A number of rare and endangered species occur in southern coastal scrub habitats. For example, the California gnatcatcher is a threatened bird species endemic to the coastal sage scrublands. Other endemic fauna includes the El Segundo blue butterfly in the LAX dunes.
The endangered Torrey pine is the dominant tree at Torrey Pines State Reserve in San Diego, one of only two known stands of this pine species. Terrace California coastal prairie California coastal sage and chaparral ecoregion In: Mayer KE and Laudenslayer WF. A Guide to Wildlife Habitats of California. Sacramento, CA: California Department of Fish and Game. Schoenherr, Allan A.. A Natural History of California. Berkeley, CA: University of California Press. "California coastal sage scrub and chaparral". Terrest
Mexico the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States. Covering 2,000,000 square kilometres, the nation is the fifth largest country in the Americas by total area and the 13th largest independent state in the world. With an estimated population of over 120 million people, the country is the eleventh most populous state and the most populous Spanish-speaking state in the world, while being the second most populous nation in Latin America after Brazil. Mexico is a federation comprising 31 states and Mexico City, a special federal entity, the capital city and its most populous city. Other metropolises in the state include Guadalajara, Puebla, Tijuana and León. Pre-Columbian Mexico dates to about 8000 BC and is identified as one of five cradles of civilization and was home to many advanced Mesoamerican civilizations such as the Olmec, Teotihuacan, Zapotec and Aztec before first contact with Europeans. In 1521, the Spanish Empire conquered and colonized the territory from its politically powerful base in Mexico-Tenochtitlan, administered as the viceroyalty of New Spain.
Three centuries the territory became a nation state following its recognition in 1821 after the Mexican War of Independence. The post-independence period was tumultuous, characterized by economic inequality and many contrasting political changes; the Mexican–American War led to a territorial cession of the extant northern territories to the United States. The Pastry War, the Franco-Mexican War, a civil war, two empires, the Porfiriato occurred in the 19th century; the Porfiriato was ended by the start of the Mexican Revolution in 1910, which culminated with the promulgation of the 1917 Constitution and the emergence of the country's current political system as a federal, democratic republic. Mexico has the 11th largest by purchasing power parity; the Mexican economy is linked to those of its 1994 North American Free Trade Agreement partners the United States. In 1994, Mexico became the first Latin American member of the Organisation for Economic Co-operation and Development, it is classified as an upper-middle income country by the World Bank and a newly industrialized country by several analysts.
The country is considered both a regional power and a middle power, is identified as an emerging global power. Due to its rich culture and history, Mexico ranks first in the Americas and seventh in the world for number of UNESCO World Heritage Sites. Mexico is an ecologically megadiverse country, ranking fourth in the world for its biodiversity. Mexico receives a huge number of tourists every year: in 2018, it was the sixth most-visited country in the world, with 39 million international arrivals. Mexico is a member of the United Nations, the World Trade Organization, the G8+5, the G20, the Uniting for Consensus group of the UN, the Pacific Alliance trade bloc. Mēxihco is the Nahuatl term for the heartland of the Aztec Empire, namely the Valley of Mexico and surrounding territories, with its people being known as the Mexica, it is believed to be a toponym for the valley which became the primary ethnonym for the Aztec Triple Alliance as a result, although it could have been the other way around.
In the colonial era, back when Mexico was called New Spain this territory became the Intendency of Mexico and after New Spain achieved independence from the Spanish Empire it came to be known as the State of Mexico with the new country being named after its capital: the City of Mexico, which itself was founded in 1524 on top of the ancient Mexica capital of Mexico-Tenochtitlan. Traditionally, the name Tenochtitlan was thought to come from Nahuatl tetl and nōchtli and is thought to mean "Among the prickly pears rocks". However, one attestation in the late 16th-century manuscript known as "the Bancroft dialogues" suggests the second vowel was short, so that the true etymology remains uncertain; the suffix -co is the Nahuatl locative, making the word a place name. Beyond that, the etymology is uncertain, it has been suggested that it is derived from Mextli or Mēxihtli, a secret name for the god of war and patron of the Mexica, Huitzilopochtli, in which case Mēxihco means "place where Huitzilopochtli lives".
Another hypothesis suggests that Mēxihco derives from a portmanteau of the Nahuatl words for "moon" and navel. This meaning might refer to Tenochtitlan's position in the middle of Lake Texcoco; the system of interconnected lakes, of which Texcoco formed the center, had the form of a rabbit, which the Mesoamericans pareidolically associated with the moon rabbit. Still another hypothesis suggests that the word is derived from Mēctli, the name of the goddess of maguey; the name of the city-state was transliterated to Spanish as México with the phonetic value of the letter x in Medieval Spanish, which represented the voiceless postalveolar fricative. This sound, as well as the voiced postalveolar fricative, represented by a j, evolved into a voiceless velar fricative during the 16th century; this led to the use of the variant Méjico in many publications in Spanish, most notably in Spain, whereas in Mexico and most other Spanish–speaking countries, México was the preferred spelling. In recent years, the Real Academia Española, which regulates the Spanish l
The Willamette Valley is a 150-mile long valley in the Pacific Northwest region of the United States. The Willamette River flows the entire length of the valley, it is surrounded by mountains on three sides – the Cascade Range to the east, the Oregon Coast Range to the west, the Calapooya Mountains to the south, it forms the cultural and political heart of Oregon, is home to 70 percent of its population including its six largest cities: Portland, Salem, the state capital, the cities of Gresham and Beaverton in the Portland metropolitan area. Eight of Oregon's ten – and 16 of its 20 – largest cities are located in the Willamette Valley; the valley's numerous waterways the Willamette River, are vital to the economy of Oregon, as they continuously deposit fertile alluvial soils across its broad, flat plain. A massively productive agricultural area, the valley was publicized in the 1820s as a'promised land of flowing milk and honey'. Throughout the 19th century it was the destination of choice for the oxen-drawn wagon trains of emigrants who made the perilous journey along the Oregon Trail.
Today the valley is considered synonymous with "Oregon Wine Country", as it contains more than 19,000 acres of vineyards and 500+ wineries. Much of the Willamette's fertility is derived from a series of massive ice-age floods that came from Lake Missoula in Montana and scoured across Eastern Washington, sweeping its topsoil down the Columbia River Gorge; when floodwaters met log- and ice-jams at Kalama in southwest Washington, the water caused a backup that filled the entire Willamette Valley to a depth of 300 to 400 feet above current sea level. Some geologists suggest that the Willamette Valley flooded in this manner multiple times during the last ice age. If floodwaters of that magnitude covered Portland in 2010, only the tops of the West Hills, Mount Tabor, Rocky Butte, Kelley Butte and Mount Scott would be visible, as would only some of the city's tallest skyscrapers. Elevations for other cities in the valley are Newberg, 175 feet; the lake drained away, leaving layered sedimentary soils on the valley floor to a height of about 180 to 200 feet above current sea level throughout the Tualatin and Willamette valleys.
Geologists have come to refer to the resulting lake as Lake Allison, named for Oregon State University geologist Ira S. Allison, who first described Willamette Silt soil in 1953 and noted its similarity to soils on the floor of former Lake Lewis in Eastern Washington. Allison is known for his work in the 1930s documenting the hundreds of non-native boulders washed down by the floods, rafted on icebergs and deposited on the valley bottom and in a ring around the lower hills surrounding the Willamette Valley. One of the most prominent of these is the Bellevue Erratic, just off Oregon Route 18 west of McMinnville, it is believed that the Willamette Meteorite was rafted by flood and ice to the location near West Linn where it was found in 1902. The valley may be loosely defined as the broad plain of the Willamette, bounded on the west by the Oregon Coast Range and on the east by the Cascade Range, it is bounded on the south by the Calapooya Mountains, which separate the headwaters of the Willamette from the Umpqua River valley about 25 miles south of Hidden Valley.
Interstate 5 runs the length of the valley. Because of differing cultural and political interests, the Portland metropolitan area and Tualatin River valley are not included in the local use of the term. Additionally, the east slopes of the Coast Ranges and the west slopes of the Cascade Range from Oakridge to Detroit Lake can be considered part of the Willamette Valley in a cultural sense, despite being mountainous areas. Cities in the valley include, from south to north, Cottage Grove, Corvallis, Dallas, Keizer, McMinnville, Oregon City, Portland, St. Helens. Parts of the following counties, from south to north, lie within the valley: Douglas, Linn, Polk, Clackamas, Washington and Columbia. Sometimes the area around Albany and Corvallis and surrounding Benton and Linn counties is referred to locally as the Mid-Valley. Marion and other counties are sometimes included in the definition of the Mid-Valley; the climate of the Willamette Valley is Mediterranean with oceanic features. This climate is characterized by dry and cloudless summers, ranging from warm to very hot, followed by cool and cloudy winters.
The precipitation pattern is distinctly Mediterranean, with little to no rainfall occurring during the summer months and over half of annual precipitation falling between November and February. Temperatures are predictable throughout the year, with daytime highs reaching the low to mid 80s in the summer and the mid 40s in the winter. Lengthy stretches of 90 °F days occur every summer reaching 100 °F. Cold days where the daytime high fails to rise above freezing are rare and may occur only two or three days per year, not at all in the lowest elevations of the valley. Temperatures of 5 °F or lower occur only about once every 25 years. Spring and fall days are between 50 and 70 degrees, with occasional surges of summer-like or winter-like temperatures that last more than a week. Precipitation varies across the valley and is correlated with elevation. Annual totals range from 36 inches (
San Joaquin River
The San Joaquin River is the longest river of Central California in the United States. The 366-mile long river starts in the high Sierra Nevada, flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, the Pacific Ocean. An important source of irrigation water as well as a wildlife corridor, the San Joaquin is among the most dammed and diverted of California's rivers. People have inhabited the San Joaquin Valley for more than 8,000 years, it was long one of the major population centers of pre-Columbian California. Starting in the late 18th century, successive waves of explorers settlers Spanish and American, emigrated to the San Joaquin basin, first exploiting driving out the indigenous tribes; the newcomers appropriated the rich natural and hydrologic resources of the watershed for use in farms and cities, but found themselves plagued by flood and drought. Because of the uniform topography of the San Joaquin Valley, floods once transformed much of the lower river into a huge inland sea.
In the 20th century, many levees and dams were built on the San Joaquin and all of its major tributaries. These engineering works changed the fluctuating nature of the river forever, cut off the Tulare Basin from the rest of the San Joaquin watershed. Once habitat for hundreds of thousands of spawning salmon and millions of migratory birds, today the river is subject to tremendous water-supply and regulation works by various federal agencies, which have reduced the flow of the river since the 20th century; the river was called many different names. The present name of the river dates to 1805–1808, when Spanish explorer Gabriel Moraga was surveying east from Mission San José in order to find possible sites for a mission. Moraga named a tributary of the river for Saint Joachim, husband of Saint Anne and father of Mary, the mother of Jesus; the name Moraga chose was applied to the entire river. In 1827, Jedediah Smith wrote in his journal that an unknown group of Native Americans called the river the Peticutry, a name, listed as an official variant in the U.
S. Geological Survey Geographic Names Information System. In the Mono language, the river is called typici h huu', which means "important or great river."An earlier name for the lower section of the San Joaquin was Rio de San Francisco, the name Father Juan Crespí gave to the river he could see entering the Sacramento-San Joaquin Delta from the south. A member of the Pedro Fages party in 1772, Crespi's vantage point was the hilltops behind modern Antioch. Another early name was Rio San Juan Bautista, the origin of, unknown; the river's source is located in the Ansel Adams Wilderness, in the south-central Sierra Nevada at the confluence of two major affluents: the Middle Fork, which rises from Thousand Island Lake at 10,000 ft above sea level, the smaller North Fork, which starts 1.8 mi southeast of Mount Lyell. The Middle Fork is considered part of the main stem; the South Fork, which begins at Martha Lake in Kings Canyon National Park and flows through Florence Lake, joins a short distance downstream.
From the mountainous alpine headwaters, the San Joaquin flows south into the foothills of the Sierra, passing through four hydroelectric dams. It emerges from the foothills at what was once the town of Millerton, the location of Friant Dam since 1942, which forms Millerton Lake. Below Friant Dam, the San Joaquin flows west-southwest out into the San Joaquin Valley – the southern part of the Great Central Valley – passing north of Fresno. With most of its water diverted into aqueducts, the river runs dry in a 150-mile section; this lack of riverwater begins in the 60 mi between Friant Dam and Mendota, where it is only replenished by the Delta-Mendota Canal and the Fresno Slough, when the Kings River is flooding. From Mendota, the San Joaquin swings northwest, passing through many different channels, some natural and some man-made. Northeast of Dos Palos, it is only joined by the Fresno and Chowchilla Rivers when they reach flood stage. Fifty miles downstream, the Merced River empties into an otherwise dry San Joaquin.
The majority of the river flows through quiet agricultural bottom lands, as a result its meandering course manages to avoid most of the urban areas and cities in the San Joaquin Valley. About 11 mi west of Modesto, the San Joaquin meets the Tuolumne. Near Vernalis, it is joined by the Stanislaus River; the river passes between Manteca and Tracy, where a pair of distributaries – the Old River and Middle River – split off from the main stem just above the Sacramento-San Joaquin Delta, a huge inverted river delta formed by sediment deposits of the Sacramento and San Joaquin Rivers. About 40 mi from the mouth, the river draws abreast to the western flank of Stockton, one of the basin's largest cities. From here to the mouth, the river is dredged as part of a navigation project, the Stockton Deep Water Ship Channel. Past the head of tide, amid the many islands of the delta, the San Joaquin is joined by two more tributaries: the Calaveras River and the larger Mokelumne; the river grows to 5,000 ft wide before ending at its confluence with the Sacramento River, in Antioch, forming the head of Suisun Bay.
The combined waters from the two rivers flow west through the Carquinez Strait and San Francisco Bay into the Pacific. The natural annual discharge of the San Joaquin before agricultural development is believed to ha
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of Canada, it flows northwest and south into the US state of Washington turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is 1,243 miles long, its largest tributary is the Snake River, its drainage basin is the size of France and extends into seven US states and a Canadian province. The fourth-largest river in the United States by volume, the Columbia has the greatest flow of any North American river entering the Pacific; the Columbia and its tributaries have been central to the region's culture and economy for thousands of years. They have been used for transportation since ancient times, linking the region's many cultural groups; the river system hosts many species of anadromous fish, which migrate between freshwater habitats and the saline waters of the Pacific Ocean. These fish—especially the salmon species—provided the core subsistence for native peoples.
In the late 18th century, a private American ship became the first non-indigenous vessel to enter the river. In the following decades, fur trading companies used the Columbia as a key transportation route. Overland explorers entered the Willamette Valley through the scenic but treacherous Columbia River Gorge, pioneers began to settle the valley in increasing numbers. Steamships along the river linked facilitated trade. Since the late 19th century and private sectors have developed the river. To aid ship and barge navigation, locks have been built along the lower Columbia and its tributaries, dredging has opened and enlarged shipping channels. Since the early 20th century, dams have been built across the river for power generation, navigation and flood control; the 14 hydroelectric dams on the Columbia's main stem and many more on its tributaries produce more than 44 percent of total US hydroelectric generation. Production of nuclear power has taken place at two sites along the river. Plutonium for nuclear weapons was produced for decades at the Hanford Site, now the most contaminated nuclear site in the US.
These developments have altered river environments in the watershed through industrial pollution and barriers to fish migration. The Columbia begins its 1,243-mile journey in the southern Rocky Mountain Trench in British Columbia. Columbia Lake – 2,690 feet above sea level – and the adjoining Columbia Wetlands form the river's headwaters; the trench is a broad and long glacial valley between the Canadian Rockies and the Columbia Mountains in BC. For its first 200 miles, the Columbia flows northwest along the trench through Windermere Lake and the town of Invermere, a region known in British Columbia as the Columbia Valley northwest to Golden and into Kinbasket Lake. Rounding the northern end of the Selkirk Mountains, the river turns south through a region known as the Big Bend Country, passing through Revelstoke Lake and the Arrow Lakes. Revelstoke, the Big Bend, the Columbia Valley combined are referred to in BC parlance as the Columbia Country. Below the Arrow Lakes, the Columbia passes the cities of Castlegar, located at the Columbia's confluence with the Kootenay River, Trail, two major population centers of the West Kootenay region.
The Pend Oreille River joins the Columbia about 2 miles north of the US–Canada border. The Columbia enters eastern Washington flowing south and turning to the west at the Spokane River confluence, it marks the southern and eastern borders of the Colville Indian Reservation and the western border of the Spokane Indian Reservation. The river turns south after the Okanogan River confluence southeasterly near the confluence with the Wenatchee River in central Washington; this C‑shaped segment of the river is known as the "Big Bend". During the Missoula Floods 10,000 to 15,000 years ago, much of the floodwater took a more direct route south, forming the ancient river bed known as the Grand Coulee. After the floods, the river found its present course, the Grand Coulee was left dry; the construction of the Grand Coulee Dam in the mid-20th century impounded the river, forming Lake Roosevelt, from which water was pumped into the dry coulee, forming the reservoir of Banks Lake. The river flows past The Gorge Amphitheatre, a prominent concert venue in the Northwest through Priest Rapids Dam, through the Hanford Nuclear Reservation.
Within the reservation is Hanford Reach, the only US stretch of the river, free-flowing, unimpeded by dams and not a tidal estuary. The Snake River and Yakima River join the Columbia in the Tri‑Cities population center; the Columbia makes a sharp bend to the west at the Washington–Oregon border. The river defines that border for the final 309 miles of its journey; the Deschutes River joins the Columbia near The Dalles. Between The Dalles and Portland, the river cuts through the Cascade Range, forming the dramatic Columbia River Gorge. No other rivers except for the Klamath and Pit River breaches the Cascades—the other rivers that flow through the range originate in or near the mountains; the headwaters and upper course of the Pit River are on the Modoc Plateau. In contrast, the Columbia cuts through the range nearly a thousand miles from its source in the Rocky Mountains; the gorge is known
San Francisco Bay
San Francisco Bay is a shallow estuary in the US state of California. It is surrounded by a contiguous region known as the San Francisco Bay Area, is dominated by the large cities of San Jose, San Francisco and Oakland. San Francisco Bay drains water from 40 percent of California. Water from the Sacramento and San Joaquin rivers, from the Sierra Nevada mountains, flow into Suisun Bay, which travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay; the Guadalupe River enters the bay at its southernmost point in San Jose. The Guadalupe drains water from the Santa Cruz mountains and Hamilton Mountain ranges in southernmost San Jose, it enters the bay at the town of Alviso. It connects to the Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is called the San Francisco Bay; the bay was designated a Ramsar Wetland of International Importance on February 2, 2012. The bay covers somewhere between 400 and 1,600 square miles, depending on which sub-bays, wetlands, so on are included in the measurement.
The main part of the bay measures three to twelve miles wide east-to-west and somewhere between 48 miles 1 and 60 miles 2 north-to-south. It is the largest Pacific estuary in the Americas; the bay was navigable as far south as San Jose until the 1850s, when hydraulic mining released massive amounts of sediment from the rivers that settled in those parts of the bay that had little or no current. Wetlands and inlets were deliberately filled in, reducing the Bay's size since the mid-19th century by as much as one third. Large areas of wetlands have been restored, further confusing the issue of the Bay's size. Despite its value as a waterway and harbor, many thousands of acres of marshy wetlands at the edges of the bay were, for many years, considered wasted space; as a result, soil excavated for building projects or dredged from channels was dumped onto the wetlands and other parts of the bay as landfill. From the mid-19th century through the late 20th century, more than a third of the original bay was filled and built on.
The deep, damp soil in these areas is subject to soil liquefaction during earthquakes, most of the major damage close to the Bay in the Loma Prieta earthquake of 1989 occurred to structures on these areas. The Marina District of San Francisco, hard hit by the 1989 earthquake, was built on fill, placed there for the Panama-Pacific International Exposition, although liquefaction did not occur on a large scale. In the 1990s, San Francisco International Airport proposed filling in hundreds more acres to extend its overcrowded international runways in exchange for purchasing other parts of the bay and converting them back to wetlands; the idea was, remains, controversial. There are five large islands in San Francisco Bay. Alameda, the largest island, was created when a shipping lane was cut to form the Port of Oakland in 1901, it is now a suburban community. Angel Island was known as "Ellis Island West" because it served as the entry point for immigrants from East Asia, it is now a state park accessible by ferry.
Mountainous Yerba Buena Island is pierced by a tunnel linking the east and west spans of the San Francisco–Oakland Bay Bridge. Attached to the north is the artificial and flat Treasure Island, site of the 1939 Golden Gate International Exposition. From the Second World War until the 1990s, both islands served as military bases and are now being redeveloped. Isolated in the center of the Bay is Alcatraz, the site of the famous federal penitentiary; the federal prison on Alcatraz Island no longer functions, but the complex is a popular tourist site. Despite its name, Mare Island in the northern part of the bay is a peninsula rather than an island. San Francisco Bay is thought to represent a down-warping of the Earth's crust between the San Andreas Fault to the west and the Hayward Fault to the east, though the precise nature of this remains under study. About 560,000 years ago, a tectonic shift caused the large inland Lake Corcoran to spill out the central valley and through the Carquinez Strait, carving out sediment and forming canyons in what is now the northern part of the San Francisco Bay and Golden Gate strait.
Until the last ice age, the basin, now filled by the San Francisco Bay was a large linear valley with small hills, similar to most of the valleys of the Coast Ranges. As the great ice sheets began to melt, around 11,000 years ago, the sea level started to rise. By 5000 BC the sea level rose 300 feet; the valley become a bay, the small hills became islands. From 15,000 – 10,000 years ago, the Ohlone tribe inhabited the area, now the San Francisco Bay; the natives were displaced 5,000 years ago as the bay filled with water due to the rising sea level at the end of the ice age. The first European to see San Francisco Bay is N. de Morena, left at New Albion at Drakes Bay in Marin County, California by Sir Francis Drake in 1579 and walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769 when Spanish explorer Gaspar de Portolà, unable to find the port of Monterey, continued north close to what is now Pacifica and reached the summit of the 1,200-foot-high Sweeney Ridge, now marked as the place where he first sighted San Francisco Bay.
Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called Drakes Bay. At the time, Drakes Bay went by the name Bahia de San
Copper River (Alaska)
The Copper River or Ahtna River, Ahtna Athabascan ‘Atna’tuu, "river of the Ahtnas", Tlingit Eeḵhéeni, "river of copper", is a 290-mile river in south-central Alaska in the United States. It drains a large region of the Wrangell Mountains and Chugach Mountains into the Gulf of Alaska, it is known for its extensive delta ecosystem, as well as for its prolific runs of wild salmon, which are among the most prized stocks in the world. The river is the tenth largest in the United States, as ranked by average discharge volume at its mouth; the Copper River rises out of the Copper Glacier, which lies on the northeast side of Mount Wrangell, in the Wrangell Mountains, within Wrangell-Saint Elias National Park. It begins by flowing due north in a valley that lies on the east side of Mount Sanford, turns west, forming the northwest edge of the Wrangell Mountains and separating them from the Mentasta Mountains to the northeast, it continues to turn southeast, through a wide marshy plain to Chitina, where it is joined from the southeast by the Chitina River.
The Copper River is 290 miles long. It drops an average of about 12 feet per mile, drains more than 24,000 square miles —an area the size of West Virginia; the river runs at an average of 7 miles per hour. Downstream from its confluence with the Chitina it flows southwest, passing through a narrow glacier-lined gap in the Chugach Mountains within the Chugach National Forest east of Cordova Peak. There is an extensive area of linear sand dunes up to 250 feet in height radiating from the mouth of the Copper River. Both Miles Glacier and Childs Glacier calve directly into the river; the Copper enters the Gulf of Alaska southeast of Cordova where it creates a delta nearly 50 miles wide. The name of the river comes from the abundant copper deposits along the upper river that were used by Alaska Native population and later by settlers from the Russian Empire and the United States. Extraction of the copper resources was problematic due to navigation difficulties at the river's mouth; the construction of the Copper River and Northwestern Railway from Cordova through the upper river valley from 1908 to 1911 allowed widespread extraction of the mineral resources, in particular from the Kennecott Mine, discovered in 1898.
The mine was abandoned in 1938 and is now a ghost town tourist attraction and historic district maintained by the National Park Service. Copper River Highway runs from Cordova to the lower Copper River near Childs Glacier, following the old railroad route and ending at the reconstructed Million Dollar Bridge across the river; the Tok Cut-Off follows the Copper River Valley on the north side of the Chugach Mountains. The river's famous salmon runs arise from the use of the river watershed by over 2 million salmon each year for spawning; the extensive runs result in many unique varieties, prized for their fat content. The river's commercial salmon season is brief, beginning in May for chinook salmon and sockeye salmon for periods lasting days or hours at a time. Sport fishing by contrast is open all year long, but peak season on the Copper River lasts from August to September when the coho salmon runs; the fisheries are co-managed by the Alaska Department of Fish and Game and the Department of the Interior Federal Subsistence Board.
Management data are obtained by ADF&G at the Miles Lake sonar station and the native village of Eyak at the Baird Canyon and Canyon Creek research stations. The Copper River Delta, which extends for 700,000 acres, is the largest contiguous wetlands along the Pacific coast of North America, it is used annually by 16 million shorebirds, including the world's entire population of western sandpipers and dunlins. It is home to the world's largest population of nesting trumpeter swans and is the only known nesting site for the dusky Canada goose subspecies. List of rivers of Alaska Brabets, Timothy P.. Geomorphology of the Lower Copper River, Alaska. Washington, D. C.: U. S. Department of the Interior, U. S. Geological Survey. Ecotrust Copper River Program Copper River salmon habitat management study Prepared for Ecotrust by Marie E. Lowe of the Institute of Social and Economic Research, hosted by Alaska State Publications Program Alaska Department of Fish and Game: Copper River Salmon Eyak Preservation Council Nature Conservancy: Copper River Delta The Copper River Watershed Project NVE Fisheries Research and Seasonal Employment on the Copper River Cordova District Fishermen United Wrangell-St.
Elias National Park information Copper River | Chitina Dipnet Fishery Escapement Charts