In modern mapping, a topographic map is a type of map characterized by large-scale detail and quantitative representation of relief using contour lines, but using a variety of methods. Traditional definitions require a topographic map to show both man-made features. A topographic survey is published as a map series, made up of two or more map sheets that combine to form the whole map. A contour line is a line connecting places of equal elevation. Natural Resources Canada provides this description of topographic maps:These maps depict in detail ground relief, forest cover, administrative areas, populated areas, transportation routes and facilities, other man-made features. Other authors define topographic maps by contrasting them with another type of map. However, in the vernacular and day to day world, the representation of relief is popularly held to define the genre, such that small-scale maps showing relief are called "topographic"; the study or discipline of topography is a much broader field of study, which takes into account all natural and man-made features of terrain.
Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms; this is in contrast to older cadastral surveys, which show property and governmental boundaries. The first multi-sheet topographic map series of an entire country, the Carte géométrique de la France, was completed in 1789; the Great Trigonometric Survey of India, started by the East India Company in 1802 taken over by the British Raj after 1857 was notable as a successful effort on a larger scale and for determining heights of Himalayan peaks from viewpoints over one hundred miles distant. Topographic surveys were prepared by the military to assist in planning for battle and for defensive emplacements; as such, elevation information was of vital importance. As they evolved, topographic map series became a national resource in modern nations in planning infrastructure and resource exploitation. In the United States, the national map-making function, shared by both the Army Corps of Engineers and the Department of the Interior migrated to the newly created United States Geological Survey in 1879, where it has remained since.1913 saw the beginning of the International Map of the World initiative, which set out to map all of Earth's significant land areas at a scale of 1:1 million, on about one thousand sheets, each covering four degrees latitude by six or more degrees longitude.
Excluding borders, each sheet was up to 66 cm wide. Although the project foundered, it left an indexing system that remains in use. By the 1980s, centralized printing of standardized topographic maps began to be superseded by databases of coordinates that could be used on computers by moderately skilled end users to view or print maps with arbitrary contents and scale. For example, the Federal government of the United States' TIGER initiative compiled interlinked databases of federal and local political borders and census enumeration areas, of roadways and water features with support for locating street addresses within street segments. TIGER was used in the 1990 and subsequent decennial censuses. Digital elevation models were compiled from topographic maps and stereographic interpretation of aerial photographs and from satellite photography and radar data. Since all these were government projects funded with taxes and not classified for national security reasons, the datasets were in the public domain and usable without fees or licensing.
TIGER and DEM datasets facilitated Geographic information systems and made the Global Positioning System much more useful by providing context around locations given by the technology as coordinates. Initial applications were professionalized forms such as innovative surveying instruments and agency-level GIS systems tended by experts. By the mid-1990s user-friendly resources such as online mapping in two and three dimensions, integration of GPS with mobile phones and automotive navigation systems appeared; as of 2011, the future of standardized, centrally printed topographical maps is left somewhat in doubt. Topographic maps have multiple uses in the present day: any type of geographic planning or large-scale architecture; the various features shown on the map are represented by conventional symbols. For example, colors can be used to indicate a classification of roads; these signs are explained in the margin of the map, or on a separately published characteristic sheet. Topographic maps are commonly called contour maps or topo maps.
In the United States, where the primary national series is organized by a strict 7.5-minute grid, they are called topo quads or quadrangles. Topographic maps conventionally show land contours, by means of contour lines. Contour lines are curves. In other words, every point on the marked line of 100 m elevation is 100 m above mean sea level; these maps show
Sierra Nevada (U.S.)
The Sierra Nevada is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies in Nevada; the Sierra Nevada is part of the American Cordillera, a chain of mountain ranges that consists of an continuous sequence of such ranges that form the western "backbone" of North America, Central America, South America and Antarctica. The Sierra runs 400 miles north-to-south, is 70 miles across east-to-west. Notable Sierra features include the largest alpine lake in North America; the Sierra is home to three national parks, twenty wilderness areas, two national monuments. These areas include Yosemite and Kings Canyon National Parks; the character of the range is shaped by its ecology. More than one hundred million years ago during the Nevadan orogeny, granite formed deep underground; the range started to uplift four million years ago, erosion by glaciers exposed the granite and formed the light-colored mountains and cliffs that make up the range.
The uplift caused a wide range of elevations and climates in the Sierra Nevada, which are reflected by the presence of five life zones. Uplift continues due to faulting caused by tectonic forces, creating spectacular fault block escarpments along the eastern edge of the southern Sierra; the Sierra Nevada has a significant history. The California Gold Rush occurred in the western foothills from 1848 through 1855. Due to inaccessibility, the range was not explored until 1912; the Sierra Nevada lies in Central and Eastern California, with a small but important spur extending into Nevada. West-to-east, the Sierra Nevada's elevation increases from 1,000 feet in the Central Valley to heights of about 14,000 feet at its crest 50–75 miles to the east; the east slope forms the steep Sierra Escarpment. Unlike its surroundings, the range receives a substantial amount of snowfall and precipitation due to orographic lift; the Sierra Nevada's irregular northern boundary stretches from the Susan River and Fredonyer Pass to the North Fork Feather River.
It represents where the granitic bedrock of the Sierra Nevada dives below the southern extent of Cenozoic igneous surface rock from the Cascade Range. It is bounded on the west by California's Central Valley and on the east by the Basin and Range Province; the southern boundary is at Tehachapi Pass. Physiographically, the Sierra is a section of the Cascade-Sierra Mountains province, which in turn is part of the larger Pacific Mountain System physiographic division; the California Geological Survey states that "the northern Sierra boundary is marked where bedrock disappears under the Cenozoic volcanic cover of the Cascade Range." The range is drained on its western slope by the Central Valley watershed, which discharges into the Pacific Ocean at San Francisco. The northern third of the western Sierra is part of the Sacramento River watershed, the middle third is drained by the San Joaquin River; the southern third of the range is drained by the Kings, Kaweah and Kern rivers, which flow into the endorheic basin of Tulare Lake, which overflows into the San Joaquin during wet years.
The eastern slope watershed of the Sierra is much narrower. From north to south, the Susan River flows into intermittent Honey Lake, the Truckee River flows from Lake Tahoe into Pyramid Lake, the Carson River runs into Carson Sink, the Walker River into Walker Lake. Although none of the eastern rivers reach the sea, many of the streams from Mono Lake southwards are diverted into the Los Angeles Aqueduct which provides water to Southern California; the height of the mountains in the Sierra Nevada increases from north to south. Between Fredonyer Pass and Lake Tahoe, the peaks range from 5,000 feet to more than 9,000 feet; the crest near Lake Tahoe is 9,000 feet high, with several peaks approaching the height of Freel Peak. Farther south, the highest peak in Yosemite National Park is Mount Lyell; the Sierra rises to 14,000 feet with Mount Humphreys near Bishop, California. Near Lone Pine, Mount Whitney is at 14,505 feet, the highest point in the contiguous United States. South of Mount Whitney, the elevation of the range dwindles.
The crest elevation is 10,000 feet near Lake Isabella, but south of the lake, the peaks reach to only a modest 8,000 feet. There are several notable geographical features in the Sierra Nevada: Lake Tahoe is a large, clear freshwater lake in the northern Sierra Nevada, with an elevation of 6,225 ft and an area of 191 sq mi. Lake Tahoe lies between a spur of the Sierra. Hetch Hetchy Valley, Yosemite Valley, Kings Canyon, Kern Canyon are examples of many glacially-scoured canyons on the west side of the Sierra. Yosemite National Park is filled with notable features such as waterfalls, granite domes, high mountains and meadows. Groves of Giant Sequoia
U.S. Route 50 in California
U. S. Route 50 in the state of California runs east from Interstate 80 in West Sacramento to the Nevada state line in South Lake Tahoe. A portion in Sacramento has the unsigned designation of Interstate 305; the western half of the highway in California is a four-or-more-lane divided highway built to freeway standards, known as the El Dorado Freeway outside of downtown Sacramento. US 50 continues as an undivided highway with one eastbound lane and two westbound lanes until the route reaches the canyon of the South Fork American River at Riverton; the remainder of the highway, which climbs along and out of the canyon over the Sierra Nevada at Echo Summit and into the Lake Tahoe Basin, is a two-lane road. The US 50 corridor is a historic one, used by many 49ers who came to California during the Gold Rush as well as the Pony Express. In 1895, part of the present-day route was designated as California's first state highway, it was designated as one of two routes of the Lincoln Highway across the Sierra Nevada.
Much of US 50 was constructed during the initial construction of the California state highway system. US 50 begins in West Sacramento, where I-80 leaves the West Sacramento Freeway onto a bypass of Sacramento; the old route of I-80 through Sacramento is signed as US 50 and Business 80 in the western section and Business 80 in the eastern section. Business 80 overlaps US 50 on the West Sacramento Freeway to the split with SR 275 over the Sacramento River on the Pioneer Memorial Bridge and across I-5 to SR 99. Beginning in 2016, signs on this section are being updated to remove references to Business 80 and instead sign the route only as US Highway 50. US 50 is part Interstate Highway as well, carrying the unsigned designation of Interstate 305 from I-80 to its interchange with SR 99. At the US 50/Business 80/SR 99 interchange, Business 80 splits to the north, SR 99 heads south, US 50 continues east as the El Dorado Freeway and the Lincoln Highway; this freeway parallels Folsom Boulevard and the American River east-northeasterly through the suburb of Rancho Cordova to Folsom.
Entering El Dorado County, US 50 continues eastward through the foothills of the Sierra Nevada via El Dorado Hills, Cameron Park, Shingle Springs to downtown Placerville. The freeway ends, US 50 has several at-grade intersections in Placerville, including SR 49. Leaving Placerville, the expressway through town starts, only to end several miles later; the final section of freeway begins near Camino, where the Lincoln Highway splits from US 50, ends at the east end of Pollock Pines. Just east of Pollock Pines, US 50 continues as an undivided conventional highway with one eastbound lane and two westbound lanes, entering the river canyon of the South Fork American River near Riverton and crossing to the north side of the river near Ice House Road. From Ice House Road to the crest of the Sierras, US 50 is a rising two-lane road, staying just north of the river except for a 1995 cutoff that crosses the river twice in quick succession west of Kyburz, the boyhood home of ski racer Spider Sabich. Several hairpin turns take the highway up a grade east of Strawberry, after which US 50 continues east alongside the river to its source at Echo Summit.
Echo Summit is the highest elevation U. S. Route 50 reaches in California at 7,382 feet. In 1968, it was the site of the U. S. Olympic trials for men's track and field, held at a temporary facility in the parking lot of the Nebelhorn ski area. From Echo Summit down to the Lake Tahoe Basin, the roadway descends the side of a steep hill. Where US 50 and SR 89 split, at an intersection known as "The Y", the former turns east on the four-lane Lake Tahoe Boulevard, which it follows to and along the south shore of Lake Tahoe it enters the state of Nevada. US 50 has been added to the California Freeway and Expressway System by the state legislature, is part of the National Highway System, a network of highways that are considered essential to the country's economy and mobility by the Federal Highway Administration; the highway east of SR 49 is eligible for the State Scenic Highway System, has been recognized as such except within the South Lake Tahoe city limits, meaning that it is a substantial section of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.
The earliest roads used by Europeans to cross the Sierra Nevada into California were branches of the California Trail. The first route near the present US 50 was the Carson Route, laid out in 1848 by an eastward Mormon party that wanted to avoid the Truckee Route and its deep crossings of the Truckee River; the group left Pleasant Valley, southeast of Placerville, on July 3, following Iron Mountain Ridge up to the crest of the Sierra at Carson Pass and descending through Carson Canyon into the Carson Valley. Along the Humboldt River in Nevada, the Mormons met Joseph B. Chiles, leading a westward wagon train to California, told him of their new trail. Although this new Carson Route crossed two summits — Carson Pass over the crest of the Sierra and West Pass over the Carson Spur just to the west, these crossings were easier than Donner Pass on the Truckee Route, only three fords of the Carson River were required; the route became the primary westward route into California at the start of the Gold Rush.
Through California, the general alignment of the Carson Route, in terms of today's highways, was State Route 88 over Carson Pass and Mormon Emigrant Trail and Sly Park Road to Pleasant V
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
California State Route 28
State Route 28 is a state highway in the U. S. state of California that travels along the northern shore of Lake Tahoe, starting at Route 89 in Tahoe City and ending at the Nevada state border, whereupon it becomes Nevada State Route 28. The route heads eastward, it intersects SR 267 in Kings Beach and continues to its terminus at Nevada State Route 28 at the Nevada state line. Route 28 is one of only three state routes that keep the same number in Nevada, along with Route 88 and Route 266. SR 28 is part of the California Freeway and Expressway System, but is not part of the National Highway System, a network of highways that are considered essential to the country's economy and mobility by the Federal Highway Administration. SR 28 is eligible for the State Scenic Highway System, but it is not designated as a scenic highway by the California Department of Transportation. Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, do not reflect current mileage.
R reflects a realignment in the route since M indicates a second realignment, L refers an overlap due to a correction or change, T indicates postmiles classified as temporary. Segments that remain unconstructed or have been relinquished to local control may be omitted; the entire route is in Placer County. California Roads portal Caltrans: Route 28 highway conditions California Highways: SR 28 California @ AARoads.com - State Route 28
Sierra Peaks Section
The Sierra Peaks Section is a mountaineering society within the Angeles Chapter of the Sierra Club that serves to provide mountaineering activities for Sierra Club members in the Sierra Nevada, to honor mountaineers who have summited Sierra Nevada peaks. The Sierra Peaks Section was established in 1955; the Section maintains historic summit registers at Bancroft Library on the University of California, Berkeley campus. To become a member of the SPS, one must be a Sierra Club member and have climbed at least six peaks on the SPS List. For verification purposes, two of those ascents must be done on an official SPS trip. Accomplished members are award with emblems, with the following grades: Third List Completion Second List Completion First List Completion Master Emblem Senior Emblem EmblemUpon receiving one of the normal emblems, members may be recognized with one of the following additional emblems, which are not ranked: Geographic Emblem Explorer Emblem To the general public, they are most known for their peak bagging list, created in 1955, a product of the Sierra Club's long legacy of promoting climbing in the Sierra Nevada.
Completing the list is prestigious in American mountaineering circles, climbers who complete the list are cited as having done so. The list is divided into three levels of importance; the Emblem peaks are considered the most iconic peaks of the Sierra Nevada, to summit all of them is the goal of many peak baggers and alpinists. Mountaineers peaks are less notable peaks known for presenting mountaineering challenges. There are the numerous general peaks of lesser note; the list is an example of a subjective "decision by committee" list with the peaks on the list being determined by the Sierra Club. Peaks are added or removed from the list due to a variety of factors, such as accessibility and interest; the list is followed by thousands of hikers and has been noted in numerous books and guides on the Sierra Nevada. There are 15 Emblem peaks, 35 Mountaineers peaks, 197 general peaks, for a total of 247 peaks; the number of peaks is traditionally set at 248, the original number of peaks listed in 1955.
The elevations listed below are those described on the list, may not be the actual elevations of those peaks, although they are accurate to within 50 feet. Other peak bagging lists: New England Fifty Finest Adirondack High Peaks Secor, R. J.. The High Sierra: peaks, trail. Seattle, WA: Mountaineers Books. ISBN 978-0-89886-971-2. Official web site
U.S. National Geodetic Survey
"United States Coast Survey" and "United States Coast and Geodetic Survey" redirect here. They are former scientific agencies of the United States government which should not be confused with the United States Coast Guard, a seagoing U. S. government law enforcement and safety agency, the modern Coast Survey, a U. S. government agency that makes nautical charts, or the United States Geological Survey, a U. S. government agency that studies earth science and makes topographical maps. The National Geodetic Survey the United States Survey of the Coast, United States Coast Survey, United States Coast and Geodetic Survey, is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication. Since its foundation in its present form in 1970, it has been part of the National Oceanic and Atmospheric Administration, of the United States Department of Commerce; the National Geodetic Survey's history and heritage are intertwined with those of other NOAA offices.
As the U. S. Coast Survey and U. S. Coast and Geodetic Survey, the agency operated a fleet of survey ships, from 1917 the Coast and Geodetic Survey was one of the uniformed services of the United States with its own corps of commissioned officers. Upon the creation of the Environmental Science Services Administration in 1965, the commissioned corps was separated from the Survey to become the Environmental Science Services Administration Corps. Upon the creation of NOAA in 1970, the ESSA Corps became the National Oceanic and Atmospheric Administration Commissioned Officer Corps. Thus, the National Geodetic Survey's ancestor organizations are the ancestors of today's NOAA Corps and Office of Coast Survey and are among the ancestors of today's NOAA fleet. In addition, today's National Institute of Standards and Technology, although long since separated from the Survey, got its start as the Survey's Office of Weights and Measures; the National Geodetic Survey is an office of NOAA's National Ocean Service.
Its core function is to maintain the National Spatial Reference System, "a consistent coordinate system that defines latitude, height, scale and orientation throughout the United States." NGS is responsible for defining the NSRS and its relationship with the International Terrestrial Reference Frame. The NSRS enables precise and accessible knowledge of where things are in the United States and its territories; the NSRS may be divided into its geometric and physical components. The official geodetic datum of the United States, NAD83 defines the geometric relationship between points within the United States in three-dimensional space; the datum may be accessed via NGS's network of survey marks or through the Continuously Operating Reference Station network of GPS reference antennas. NGS is responsible for computing the relationship between NAD83 and the ITRF; the physical components of the NSRS are reflected in its height system, defined by the vertical datum NAVD88. This datum is a network of orthometric heights obtained through spirit leveling.
Because of the close relationship between height and Earth's gravity field, NGS collects and curates terrestrial gravity measurements and develops regional models of the geoid and its slope, the deflection of the vertical. NGS is responsible for ensuring the accuracy of the NSRS over time as the North American plate rotates and deforms over time due to crustal strain, post-glacial rebound, elastic deformation of the crust, other geophysical phenomena. NGS will release new datums in 2022; the North American Terrestrial Reference Frame of 2022 will supersede NAD83 in defining the geometric relationship between the North American plate and the ITRF. United States territories on the Pacific and Mariana plates will have their own respective geodetic datums; the North American-Pacific Geopotential Datum of 2022 will separately define the height system of the United States and its territories, replacing NAVD88. It will use a geoid model accurate to 1 centimeter to relate orthometric height to ellipsoidal height measured by GPS, eliminating the need for future leveling projects.
This geoid model will be based on airborne and terrestrial gravity measurements collected by NGS's GRAV-D program as well as satellite-based gravity models derived from observations collected by GRACE, GOCE, satellite altimetry missions. NGS provides a number of other public services, it maps changing shorelines in the United States and provides aerial imagery of regions affected by natural disasters, enabling rapid damage assessment by emergency managers and members of the public. The Online Positioning and User Service processes user-input GPS data and outputs position solutions within the NSRS; the agency offers other tools for conversion between datums. The original predecessor agency of the National Geodetic Survey was the United States Survey of the Coast, created within the United States Department of the Treasury by an Act of Congress on February 10, 1807, to conduct a "Survey of the Coast." The Survey of the Coast, the United States government's first scientific agency, represented the interest of the administration of President Thomas Jefferson in science and the stimulation of international trade by using scientific surveying methods to chart t