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
Blythe was named after Thomas H. Blythe, a San Francisco financier, who established primary water rights to the Colorado River in the region in 1877. The city was incorporated on July 21,1916, the population was 20,817 at the 2010 census. Calloway made preliminary surveys and filed claims under the Swamp Land Act of 1850. He interested the wealthier Thomas Henry Blythe, who was born in Mold, Wales, on July 17,1877, Blythe filed his first claim for Colorado River water on what was to become the Blythe Intake. Blythe appointed another man named George Irish as manager to assist Calloway in building an irrigation system, Calloway died in a Chemehuevi attack in March 28,1880, and was replaced by C. C. Miller, the father of Frank Augustus Miller, Thomas Blythe died on April 4,1883, his only revisit to the valley was in November 1882. After his death, the work in the valley halted and Blythes estate subsequently went into litigation between his illegitimate daughter Florence and other claimants. Frank Murphy and Ed Williams, who were involved on the industry in southeastern Arizona, came to the area in 1904 and were convinced it was well-suited for cattle.
With the Hobson brothers from Ventura County, they bought Blythes estate and formed the Palo Verde Land, who helped develop nearby Imperial Valley, was the companys general manager. On August 8,1916, the California Southern Railroad reached Blythe from the station of Rice, California. It was renamed to honor G. W, Rice, an engineer and superintendent of the railroad. The dramatic growth in the valley following this event attracted national attention, production totals increased annually from virtually nothing to near $8,000,000 in few years, primarily from cotton and cotton seed shipped to the ports. The lower cotton prices in 1920 ended this prosperous time, the Atchison and Santa Fe Railway began leasing the line in 1921 and acquired it in the end of 1942. The first automobile bridge over the Colorado River between Blythe and Ehrenberg was constructed in 1928 to replace a ferry service. The bridges successor was built in the early 1960s and it was expanded to four lanes, in 1972, Interstate 10 was built through the city, replacing US60 and the previously decommissioned US70 in Hobsonway as the main thoroughfare.
Blythe is located near the California/Arizona border in the Colorado Desert section of the Sonoran Desert, at the junction of Interstate 10 and US95. According to the United States Census Bureau, the city has an area of 27.0 square miles. Nearby communities include Lost Lake and Vidal to the north, Ripley to the south, Desert Center to the west, major cities in the region include Yuma, Phoenix, San Bernardino and Las Vegas
National Wilderness Preservation System
The National Wilderness Preservation System of the United States protects federally managed wilderness areas designated for preservation in their natural condition. Activity on formally designated wilderness areas is coordinated by the National Wilderness Preservation System. Wilderness areas are managed by four federal land management agencies, the National Park Service, the U. S. Forest Service, the U. S. Fish and Wildlife Service, and the Bureau of Land Management. As of 2015, there are 765 designated wilderness areas, totaling 109,129,657 acres, during the 1950s and 1960s, as the American transportation system was on the rise, concern for clean air and water quality began to grow. A conservation movement began to place with the intent of establishing designated wilderness areas. Howard Zahniser created the first draft of the Wilderness Act in 1956 and it took nine years and 65 rewrites before the Wilderness Act was finally passed in 1964. The Wilderness Act of 1964, which established the NWPS, was signed into law by President Lyndon B.
Johnson on September 3,1964, the first national forest wilderness areas were established by the Wilderness Act itself. The Great Swamp in New Jersey became the first National Wildlife Refuge with formally designated wilderness in 1968, Wilderness areas in national parks followed, beginning with the designation of wilderness in part of Craters of the Moon National Monument in Idaho in 1970. A smaller spike in 1984 came with the passage of many bills establishing national forest wilderness areas identified by the Forest Services Roadless Area Review and Evaluation process. Over 200 wilderness areas have been created within Bureau of Land Management administered lands since then, as of August 2008, a total of 704 separate wilderness areas, encompassing 107,514,938 acres, had become part of the National Wilderness Preservation System. With the passage of the Omnibus Public Lands Act in March 2009, as of September 2015, the system includes 765 wilderness areas totaling 109,129,657 acres. On federal lands in the United States, Congress may designate an area as wilderness under the provisions of the Wilderness Act of 1964.
Congress reviews these cases on a state by state basis and determines which areas, there have been multiple occasions in which congress designated more federal land than had been recommended by the nominating agency. The Wilderness Act provides criteria for lands being considered for wilderness designation, Wilderness areas are subject to specific management restrictions, human activities are limited to non-motorized recreation, scientific research, and other non-invasive activities. During these activities, patrons are asked to abide by the Leave No Trace policy and this policy sets guidelines for using the wilderness responsibly, and leaving the area as it was before usage. When closely observed, the Leave No Trace ethos ensures that wilderness areas remain untainted by human interaction, Wilderness areas fall into IUCN protected area management category Ia or Ib. Wilderness areas are parts of parks, wildlife refuges, national forests. Initially, the NWPS included 34 areas protecting 9.1 million acres in the national forests, there are 762 wilderness areas in the NWPS, preserving 108,916,684 acres
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
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
Big Maria Mountains
The Big Maria Mountains are located in the southeastern part of the U. S. state of California, near the Colorado River and Arizona. The range lies between Blythe and Vidal, and west of U. S. Route 95 in California, the mountains are home to the Eagle Nest Mine and reach an elevation of 1,030 meters. A power line runs from Parker Dam to Yuma, Arizona runs through the range. A smaller range, the Little Maria Mountains, lie to the west of the Big Marias, the Big Maria Mountains are one of several ranges that constitute the Maria Fold and Thrust Belt. The Maria Fold and Thrust Belt underwent generally thick-skinned North-South trending crustal shortening in the Cretaceous, foxtail cactus and California barrel cactus dot the landscape, and a Burro mule deer herd relies on the Colorado River for survival. The Big Maria Mountains Wilderness Area is managed by the Bureau of Land Management for recreation, the terrain of the Big Maria Mountains within the wilderness area varies from gently sloping Alluvial fans to numerous rough, craggy peaks disjointed by steep canyons.
The northern boundary lies south of a major known as Big Wash, and the eastern edge parallels U. S. Route 95 in California. The west and south boundaries follow power lines and contours along the base of the mountains, the Bureau of Land Management manages the Rice Valley Wilderness in and near the Big Maria Mountains. The broad, flat plains of Rice Valley and the tip of the steep. A system of small dunes rising 30 to 40 feet above the surface form a long, the valley is part of a massive Erg-sand sheet which extends from Cadiz Valley through Ward Valley, representing a part of one of the largest dune systems in the Desert Region of California
The town, located on present-day California State Route 62 between Twentynine Palms and the Colorado River, grew around a Santa Fe Railroad subdivision and siding. It was the point of the abandoned Ripley Branch that goes through Blythe to Ripley. While the airfields date of construction is unknown, it was not depicted on a 1932 Los Angeles Airways Chart, Rice Army Airfield consisted of two intersecting paved 5,000 foot runways and numerous dispersal pads south of the runways. In 1944 the airfield was transferred from Thermal Army Airfield to March Field, operations at Rice Field were ended by August 1944, and the field was declared surplus on 31 October 1944. The desert training area near Rice Army Airfield was at one time considered as the site for the worlds first atomic-bomb test, instead, a site near Alamogordo, New Mexico, was chosen. Rice became noted for its Rice Shoe Tree, a lone tamarisk on a turnout just south of the highway, for reasons unknown, it became customary for travelers on Highway 62 to and from the Colorado River to hang an old shoe on the trees branches.
The tree was featured on Californias Gold, a PBS program hosted by Huell Howser, the tree burned to the ground in 2003 in a fire of suspicious origin, after which a shoe garden replaced it, a fence on which people hang shoes instead. Travelers still stop to spell their names on the nearby Arizona, hand-assembled graffiti lines the railroad for the entire distance that it parallels Highway 62. At some point during the period 1944–48, Rice Army Airfield was renamed Rice Airport and began operations as a civilian airport. Between 1952 and 1955, Rice Airport was changed to a private field, as of 2007, no standing structures remain and little evidence exists of the airports former existence. There are no standing buildings and no residents in Rice at present, a hand-painted sign on the western outskirts of the town once announced that the townsite was for sale, but that sign has since been removed. The only building which remains in any condition is a service station. In 2010, there was filming for the 2011 movie Fast Five near Rice and it was featured during the train scene in the beginning of the movie
Riverside County, California
Riverside County, California is one of fifty-eight counties in the U. S. state of California. As of the 2010 census, the population was 2,189,641, making it the 4th-most populous county in California, the name was derived from the city of Riverside, which is the county seat. Riverside County is included in the Riverside-San Bernardino-Ontario, CA Metropolitan Statistical Area, the county is included in the Los Angeles-Long Beach, CA Combined Statistical Area. There is a concentration of sprawling tract housing communities around Riverside and along the Interstate 10,15. Roughly rectangle-shaped, Riverside County covers 7,208 square miles in Southern California, the county is mostly desert in the central and eastern portions, but has a Mediterranean climate in the western portion. Most of Joshua Tree National Park is located in the county, the resort cities of Palm Springs, Palm Desert, Indian Wells, La Quinta, Rancho Mirage, and Desert Hot Springs are all located in the Coachella Valley region of Riverside County.
Large numbers of Los Angeles area workers have moved to the county in recent years to take advantage of affordable housing. Along with neighboring San Bernardino County, it was one of the fastest growing regions in the prior to the recent changes in the regional economy. In addition, but significant, numbers of people have been moving into Southwest Riverside County from the San Diego-Tijuana metropolitan area, the cities of Temecula and Murrieta accounted for 20% of the increase in population of the county between 2000 and 2007. The indigenous peoples of what is now Riverside County are the Luiseño, Cupeño, the Luiseño lived in the Aguanga and Temecula Basins, Elsinore Trough and eastern Santa Ana Mountains and southward into San Diego County. The Cahullia lived to the east and north of the Luiseño in the valleys, Santa Rosa and San Jacinto Mountains. The first European settlement in the county was a Mission San Luis Rey de Francia estancia or farm and grapes were grown here. In 1819, the Mission granted land to Leandro Serrano, mayordomo of San Antonio de Pala Asistencia for the Mission of San Luis Rey for Rancho Temescal, following Mexican independence and the 1833 confiscation of Mission lands, more ranchos were granted.
New Mexican colonists founded the town of La Placita on the east side of the Santa Ana River at the extremity of what is now the city of Riverside in 1843. When the initial 27 California counties were established in 1850 the area known as Riverside County was divided between Los Angeles County and San Diego County. In 1853 the eastern part of Los Angeles County was used to create San Bernardino County, between 1891 and 1893 several proposals, and legislative attempts, were put forth to form new counties in Southern California. These proposals included one for a Pomona County and one for a San Jacinto County, none of the proposals were adopted until a measure to create Riverside County was signed by Governor Henry H. Markham on March 11,1893. The new county was created from parts of San Bernardino County, on May 2,1893, seventy percent of voters approved the formation of Riverside County
Bureau of Land Management
President Harry S. Truman created the BLM in 1946 by combining two existing agencies, the General Land Office and the Grazing Service. Most BLM public lands are located in these 12 western states, Arizona, Colorado, Montana, New Mexico, Utah and Wyoming. The mission of the BLM is to sustain the health, originally BLM holdings were described as land nobody wanted because homesteaders had passed them by. All the same, ranchers hold nearly 18,000 permits, the agency manages 221 wilderness areas,23 national monuments and some 636 other protected areas as part of the National Landscape Conservation System totaling about 30 million acres. There are more than 63,000 oil and gas wells on BLM public lands, total energy leases generated approximately $5.4 billion in 2013, an amount divided among the Treasury, the states, and Native American groups. The BLMs roots go back to the Land Ordinance of 1785 and these laws provided for the survey and settlement of the lands that the original 13 colonies ceded to the federal government after the American Revolution.
As additional lands were acquired by the United States from Spain and other countries, the United States Congress directed that they be explored, during the Revolutionary War, military bounty land was promised to soldiers who fought for the colonies. After the war, the Treaty of Paris of 1783, signed by the United States, France, in the 1780s, other states relinquished their own claims to land in modern-day Ohio. By this time, the United States needed revenue to function, Land was sold so that the government would have money to survive. In order to sell the land, surveys needed to be conducted, the Land Ordinance of 1785 instructed a geographer to oversee this work as undertaken by a group of surveyors. The first years of surveying were completed by trial and error, once the territory of Ohio had been surveyed, in 1812, Congress established the General Land Office as part of the Department of the Treasury to oversee the disposition of these federal lands. By the early 1800s, promised bounty land claims were finally fulfilled, over the years, other bounty land and homestead laws were enacted to dispose of federal land.
Several different types of patents existed and these include cash entry, homestead, military warrants, mineral certificates, private land claims, state selections, town sites, and town lots. A system of land offices spread throughout the territories, patenting land that was surveyed via the corresponding Office of the Surveyor General of a particular territory. This pattern gradually spread across the entire United States, the laws that spurred this system with the exception of the General Mining Law of 1872 and the Desert Land Act of 1877 have since been repealed or superseded. The Mineral Leasing Act of 1920 allowed leasing and production of selected commodities, such as coal, gas, the Taylor Grazing Act of 1934 established the United States Grazing Service to manage the public rangelands by establishment of advisory boards that set grazing fees. The Oregon and California Revested Lands Sustained Yield Management Act of 1937, commonly referred as the O&C Act, in 1946, the Grazing Service was merged with the General Land Office to form the Bureau of Land Management within the Department of the Interior.
It took several years for new agency to integrate and reorganize
The Riverside Mountains are a mountain range in Riverside County, California. The town of Vidal, California is located in the West Riverside Mountains, the Riverside Mountains are in the Colorado Desert, in the Lower Colorado River Valley region. They are southeast of the Turtle Mountains and north of the Big Maria Mountains, the high point of the range is 2,252 feet. The Riverside Mountains Wilderness Area is managed by the Bureau of Land Management, the Colorado River parallels this wilderness on its eastern edge. The landscape varies from gently sloping bajadas to steep, rugged interiors, washes emerging from canyons divide the bajadas below. Numerous peaks in the Riverside Mountains give this small range a rough, two sensitive plant species, the foxtail cactus and California barrel cactus, and a small herd of Burro deer live in the Riverside range. The Riverside Mountains are one of several ranges that constitute the Maria Fold, the Maria Fold and Thrust Belt underwent generally thick-skinned North-South trending crustal shortening in the Cretaceous.
The Riverside Mountains contain rocks from both the lower and upper plates of a detachment fault and metamorphic core complex system as a result of the Miocene-age extension. The upper plate of the detachment fault consists of a sedimentary basin containing Tertiary-age syntectonic volcanic units, conglomerates