A narrow-gauge railway is a railway with a track gauge narrower than standard 1,435 mm. Most narrow-gauge railways are between 600 1,067 mm. Since narrow-gauge railways are built with tighter curves, smaller structure gauges, lighter rails, they can be less costly to build and operate than standard- or broad-gauge railways. Lower-cost narrow-gauge railways are built to serve industries and communities where the traffic potential would not justify the cost of a standard- or broad-gauge line. Narrow-gauge railways have specialized use in mines and other environments where a small structure gauge necessitates a small loading gauge, they have more general applications. Non-industrial, narrow-gauge mountain railways are common in the Rocky Mountains of the United States and the Pacific Cordillera of Canada, Switzerland, the former Yugoslavia and Costa Rica. In some countries, narrow gauge is the standard. Narrow-gauge trams metre-gauge, are common in Europe. In general, a narrow-gauge railway is narrower than 1,435 mm.
Because of historical and local circumstances, the definition of a narrow-gauge railway varies. The earliest recorded railway appears in Georgius Agricola's 1556 De re metallica, which shows a mine in Bohemia with a railway of about 2 ft gauge. During the 16th century, railways were restricted to hand-pushed, narrow-gauge lines in mines throughout Europe. In the 17th century, mine railways were extended to provide transportation above ground; these lines were industrial. These railways were built to the same narrow gauge as the mine railways from which they developed; the world's first steam locomotive, built in 1802 by Richard Trevithick for the Coalbrookdale Company, ran on a 3 ft plateway. The first commercially successful steam locomotive was Matthew Murray's Salamanca built in 1812 for the 4 ft 1 in Middleton Railway in Leeds. Salamanca was the first rack-and-pinion locomotive. During the 1820s and 1830s, a number of industrial narrow-gauge railways in the United Kingdom used steam locomotives.
In 1842, the first narrow-gauge steam locomotive outside the UK was built for the 1,100 mm -gauge Antwerp-Ghent Railway in Belgium. The first use of steam locomotives on a public, passenger-carrying narrow-gauge railway was in 1865, when the Ffestiniog Railway introduced passenger service after receiving its first locomotives two years earlier. Many narrow-gauge railways were part of industrial enterprises and served as industrial railways, rather than general carriers. Common uses for these industrial narrow-gauge railways included mining, construction, tunnelling and conveying agricultural products. Extensive narrow-gauge networks were constructed in many parts of the world. Significant sugarcane railways still operate in Cuba, Java, the Philippines, Queensland, narrow-gauge railway equipment remains in common use for building tunnels; the first use of an internal combustion engine to power a narrow-gauge locomotive was in 1902. F. C. Blake built a 7hp petrol locomotive for the Richmond Main Sewerage Board sewage plant at Mortlake.
This 2 ft 9 in gauge locomotive was the third petrol-engined locomotive built. Extensive narrow-gauge rail systems served the front-line trenches of both sides in World War I, they were a short-lived military application, after the war the surplus equipment created a small boom in European narrow-gauge railway building. Narrow-gauge railways cost less to build because they are lighter in construction, using smaller cars and locomotives, smaller bridges and tunnels, tighter curves. Narrow gauge is used in mountainous terrain, where engineering savings can be substantial, it is used in sparsely populated areas where the potential demand is too low for broad-gauge railways to be economically viable. This is the case in parts of Australia and most of Southern Africa, where poor soils have led to population densities too low for standard gauge to be viable. For temporary railways which will be removed after short-term use, such as logging, mining or large-scale construction projects, a narrow-gauge railway is cheaper and easier to install and remove.
Such railways have vanished, due to the capabilities of modern trucks. In many countries, narrow-gauge railways were built as branch lines to feed traffic to standard-gauge lines due to lower construction costs; the choice was not between a narrow- and standard-gauge railway, but between a narrow-gauge railway and none at all. Narrow-gauge railways cannot interchange rolling stock with the standard- or broad-gauge railways with which they link, the transfer of passengers and freight require time-consuming manual labour or substantial capital expenditure; some bulk commodities, such as coal and gravel, can be mechanically transshipped, but this is time-consuming, the equipment required for the transfer is complex to maintain. If rail lines with other gauges coexist in a network, in times of peak demand i
Sangre de Cristo Range
The Sangre de Cristo Range, called the East Range locally in the San Luis Valley, is a high and narrow mountain range of the Rocky Mountains in southern Colorado in the United States, running north and south along the east side of the Rio Grande Rift. The mountains extend southeast from Poncha Pass for about 75 mi through south-central Colorado to La Veta Pass 20 mi west of Walsenburg, form a high ridge separating the San Luis Valley on the west from the watershed of the Arkansas River on the east; the Sangre de Cristo Range rises over 7,000 ft above the valleys and plains to the west and northeast. According to the USGS, the range is the northern part of the larger Sangre de Cristo Mountains, which extend through northern New Mexico. Usage of the terms "Sangre de Cristo Range" and "Sangre de Cristo Mountains" is varied. Most of the range is shared by two National Forests. Most of the northeast side is located within the San Isabel National Forest, while most of the southwest side is included in the Rio Grande National Forest.
The central part of the range is designated as the Sangre de Cristo Wilderness. The Great Sand Dunes National Park sits on the southwestern flank of the range at the edge of the San Luis Valley; the range divide is traversed by no paved roads, only by four-wheel drive and foot trails over Hayden Pass, Hermit Pass, Music Pass, Medano Pass, Mosca Pass. The highest peak in the range, located in the south, is Blanca Peak at 14,345 ft. Other well-known peaks are the fourteeners of the Crestone group: Kit Carson Mountain, Crestone Peak, Crestone Needle, Humboldt Peak. Two sub-peaks of Kit Carson Mountain, Challenger Point and Columbia Point, are named in memory of the crews of the Space Shuttle Challenger and the Space Shuttle Columbia; the range is home to many high peaks in the 13,000 to 14,000 foot range. In 1719 the Spanish explorer Antonio Valverde y Cosio named the Sangre de Cristo mountains after being impressed by the reddish hue of the snowy peaks at sunrise, alpenglow. Today tourism is the main economic activity.
The Sangre de Cristos are fault-block mountains similar to the Teton Range in Wyoming and the Wasatch Range in Utah. There are major fault lines running along both the east and west sides of the range and, in places, cutting through the range. Like all fault-block mountain ranges, the Sangre de Cristo's lack foothills which means the highest peaks rise abruptly from the valleys to the east and west, rising 7,000 ft in only a few miles in some places; the mountains were pushed up around 5 million years ago as one large mass of rock. The Sangre de Cristo range is still being uplifted today. On the west side is the San Luis Valley, a portion of the Rio Grande Rift. On the southeast side is the Raton Basin, a quiet but still active volcanic field. On the northeast side are the Wet Mountains and the Front Range, areas of Precambrian igneous and metamorphic rocks formed during the Colorado orogeny some 1.7 billion years ago and uplifted more during the Laramide orogeny. The Blanca Massif is Precambrian rock, while most of the rest of the Sangres is composed of younger Permian-Pennsylvanian rock, a mix of sedimentary conglomerates and igneous intrusions.
These sedimentary rocks originated as sediment eroded from the Ancestral Rocky Mountains. Southern Rocky Mountains Mountain ranges of Colorado Sangre de Cristo Range @ Peakbagger Table listing of all the thirteeners in Sangre de Cristo @ Pikes Peak Photo High resolution zoomable panorama of the Sangre de Cristo mountain range looking West CO & NM Sangre de Cristo Mountains
U.S. Route 160
U. S. Route 160 is a 1,465 mile long east–west United States highway in the Midwestern and Western United States; the western terminus of the route is at US 89 five miles west of Arizona. The eastern terminus is at Missouri 158 southwest of Poplar Bluff, Missouri, its route, if not its number, was made famous in song in 1975, as the road from Wolf Creek Pass to Pagosa Springs, Colorado in C. W. McCall's country music song Wolf Creek Pass. US 160 begins at US 89 near the western edge of Navajo Nation. Near Tuba City, it intersects State Route 264, it goes through Tonalea and Cow Springs before entering Kayenta, where it intersects U. S. Route 163, it continues northeast through Dennehotso has a brief overlap with U. S. Route 191 in Mexican Water, it goes east until Teec Nos Pos, where it intersects U. S. Route 64 turns northeast to go to the Four Corners and enters New Mexico. US 160 is one of the major routes crossing the Navajo Nation and in Arizona does not leave the Navajo Nation. About 0.9 miles of US 160 is located within New Mexico.
The highway travels northeast through extreme northwestern New Mexico, intersecting State Road 597, which provides access to the Four Corners Monument. US-160 along with NM-597 do not connect to any other portion of the New Mexico state highway network, requiring New Mexico Department of Transportation crews to travel through either Arizona or Colorado to access it. U. S. Route 160 enters Colorado near the Four Corners Monument, it goes northeast and intersects U. S. Route 491 turns north to enter Cortez with U. S. 491. East of Cortez, a road leads south from U. S. 160 to Mesa Verde National Park. It continues east to Durango, where it intersects U. S. Route 550. After overlapping with U. S. 550 south of Durango, U. S. 160 turns east and meets U. S. Route 84 at Pagosa Springs, it goes northeast and crosses the Continental Divide at Wolf Creek Pass. From Wolf Creek Pass, U. S. 160 turns east at South Fork. At Monte Vista, an overlap begins with U. S. Route 285, it turns east goes northeast to go through North La Veta Pass continues east to Walsenburg, where it intersects Interstate 25.
From Walsenberg, U. S. 160 continues south with Interstate 25 to Trinidad turns northeast to intersect U. S. Route 350, it continues east, passing through the Comanche National Grassland before intersecting the concurrent U. S. Route 287 and U. S. Route 385 south of Springfield, it enters Kansas east of Walsh. US-160 enters Kansas just west of Saunders, it goes northeast to Johnson turns east to go through Ulysses. Near Sublette, it intersects U. S. Route 83 and runs concurrently southward past its intersection with U. S. Route 56, it turns east and runs concurrently with U. S. Route 54 between Plains and Meade, it continues east, runs concurrently with U. S. Route 283 and U. S. Route 183. At Medicine Lodge, it intersects U. S. Route 281, it continues east and at Wellington, intersects U. S. Route 81 and Interstate 35, on which the Kansas Turnpike is routed in the area. East of Interstate 35, it intersects U. S. Route 77 in Winfield, it goes east from Winfield turns north to Burden goes east before going south to Elk City.
It turns east and goes through Independence after being concurrent with U. S. Route 75, it continues east, is concurrent with U. S. Route 169 and intersects U. S. Route 59 at Altamont. US-160 and US-59 go into Oswego and separate. At Columbus, US-160 begins a concurrency with U. S. Route 69, which goes east to Crestline north to Frontenac, Kansas. At Crestline, it picks up a second concurrency with U. S. Route 400, which ends just south of Pittsburg, Kansas. After Frontenac, it enters Missouri. U. S. Route 160 enters Missouri west of Mindenmines. At Lamar, it intersects Interstate 49/U. S. Route 71, it goes southeast towards Springfield, where it intersects Interstate 44 and U. S. Route 60, it goes south out of Springfield into Nixa as Massey Boulevard turns east and intersects U. S. Route 65 north of Branson, it continues east to West Plains, where it intersects U. S. Route 63 ends southwest of Poplar Bluff at an intersection with U. S. Route 67. In Willard, Missouri, US 160 runs on a bypass along the southern edge of town.
The old alignment through Willard is now U. S. Route 160 Business; as commissioned in 1930 the western terminus was Colorado. In 1939, US 160 absorbed all of former route U. S. Route 450 which ran from U. S. 50 at Crescent Junction, Utah to U. S. Route 85 at Walsenburg, Colorado. In 1970 many US highways in the Four Corners region were re-aligned. U. S. 160 was diverted southwesterly from Cortez, Colorado to follow its present route past the Four Corners into Arizona, absorbing the route numbered U. S. Route 164 from 1964-1970; the portion of former US160 from Crescent Jct. to Monticello, Utah was replaced with U. S. Route 163 and the portion from Monticello to Cortez, Colorado was replaced with U. S. Route 666; the eastern terminus of US 160 was located at an intersection with U. S. Route 60 and then-U. S. Route 66 in Springfield, Missouri. In the 1950s, the terminus moved eastward across the state to an intersection with then-US 60 and then-U. S. Route 67 in Poplar Bluff; the extension between Springfield and Poplar Bluff was parallel to U.
S. Route 65 from Springfield to near Branson, where US 160 headed east across the Ozark Mountains. In 2007, the terminus was moved to its current location southwest of Poplar Bluff, eliminating a concurrency between US 160 and two ot
To cities, towns, charter townships and boroughs. The term can be used to describe municipally owned corporations. Municipal incorporation occurs when such municipalities become self-governing entities under the laws of the state or province in which they are located; this event is marked by the award or declaration of a municipal charter. A city charter or town charter or municipal charter is a legal document establishing a municipality, such as a city or town. In Canada, charters are granted by provincial authorities; the Corporation of Chennai is the oldest Municipal Corporation in the world after UK. The title "corporation" was used in boroughs from soon after the Norman conquest until the Local Government Act 2001. Under the 2001 act, county boroughs were renamed "cities" and their corporations became "city councils". After the Partition of Ireland, the corporations in the Irish Free State were Dublin, Cork and Waterford and Drogheda, Sligo and Wexford. Dún Laoghaire gained borough status in 1930 as “The Corporation of Dun Laoghaire".
Galway's borough status, lost in 1840, was restored in 1937. The New Zealand Constitution Act 1852 allowed municipal corporations to be established within the new Provinces of New Zealand; the term fell out of favour following the abolition of the Provinces in 1876. In the United States, such municipal corporations are established by charters that are granted either directly by a state legislature by means of local legislation, or indirectly under a general municipal corporation law after the proposed charter has passed a referendum vote of the affected population. Under the enterprise meaning of the term, municipal corporations are "organisations with independent corporate status, managed by an executive board appointed by local government officials, with majority public ownership"; some MOCs rely on revenue from user fees, distinguishing them from agencies and special districts funded through taxation, although this is not always the case. Municipal corporation follows a process of externalization that requires new skills and orientations from the respective local governments, follow common changes in the institutional landscape of public services.
They are argued to be more efficient than bureaucracy but have higher failure rates because of their legal and managerial autonomy. Unincorporated area German town law Municipal incorporationA Brief Summary of Municipal Incorporation Procedures by State - University of Georgia Characteristics and State Requirements for Incorporated Places - United States CensusMunicipal disincorporation / dissolutionDissolving Cities - University of California, Berkeley Municipal Disincorporation in California - California City Finance
A ZIP Code is a postal code used by the United States Postal Service in a system it introduced in 1963. The term ZIP is an acronym for Zone Improvement Plan; the basic format consists of five digits. An extended ZIP+4 code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that reference a more specific location; the term ZIP Code was registered as a servicemark by the U. S. Postal Service, but its registration has since expired; the early history and context of postal codes began with postal district/zone numbers. The United States Post Office Department implemented postal zones for numerous large cities in 1943. For example: The "16" was the number of the postal zone in the specific city. By the early 1960s, a more organized system was needed, non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963; the USPOD issued its Publication 59: Abbreviations for Use with ZIP Code on October 1, 1963, with the list of two-letter state abbreviations which are written with both letters capitalized.
An earlier list in June had proposed capitalized abbreviations ranging from two to five letters. According to Publication 59, the two-letter standard was "based on a maximum 23-position line, because this has been found to be the most universally acceptable line capacity basis for major addressing systems", which would be exceeded by a long city name combined with a multi-letter state abbreviation, such as "Sacramento, Calif." along with the ZIP Code. The abbreviations have remained unchanged, with the exception of Nebraska, changed from NB to NE in 1969 at the request of the Canadian postal administration, to avoid confusion with the Canadian province of New Brunswick. Robert Moon is considered the father of the ZIP Code; the post office only credits Moon with the first three digits of the ZIP Code, which describe the sectional center facility or "sec center." An SCF is a central mail processing facility with those three digits. The fourth and fifth digits, which give a more precise locale within the SCF, were proposed by Henry Bentley Hahn Sr.
The SCF sorts mail to all post offices with those first three digits in their ZIP Codes. The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public, most of their employees work the night shift. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the case of large cities, the last two digits coincide with the older postal zone number thus: In 1967, these became mandatory for second- and third-class bulk mailers, the system was soon adopted generally; the United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code, he was depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. In 1971 Elmira Star-Gazette reporter Dick Baumbach found out the White House was not using a ZIP Code on its envelopes.
Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the ZIP Code. In 1983, the U. S. Postal Service introduced an expanded ZIP Code system that it called ZIP+4 called "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required. In general, mail is read by a multiline optical character reader that instantly determines the correct ZIP+4 Code from the address—along with the more specific delivery point—and sprays an Intelligent Mail barcode on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 Code and two for the delivery point.
For Post Office Boxes, the general rule is. The add-on code is one of the following: the last four digits of the box number, zero plus the last three digits of the box number, or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number. However, there is no uniform rule, so the ZIP+4 Code must be looked up individually for each box; the ZIP Code is translated into an Intelligent Mail barcode, printed on the mailpiece to make it easier for automated machines to sort. A barcode can be printed by the sender, it is better to let the post office put one on. In general, the post office uses OCR technology, though in some cases a human might have to read and enter the address. Customers who send bulk mail can get a discount on postage if they have printed the barcode themselves and have presorted the mai
A county seat is an administrative center, seat of government, or capital city of a county or civil parish. The term is used in Canada, Romania and the United States. County towns have a similar function in the United Kingdom and Republic of Ireland, in Jamaica. In most of the United States, counties are the political subdivisions of a state; the city, town, or populated place that houses county government is known as the seat of its respective county. The county legislature, county courthouse, sheriff's department headquarters, hall of records and correctional facility are located in the county seat though some functions may be located or conducted in other parts of the county if it is geographically large. A county seat is but not always, an incorporated municipality; the exceptions include the county seats of counties that have no incorporated municipalities within their borders, such as Arlington County, Virginia. Ellicott City, the county seat of Howard County, is the largest unincorporated county seat in the United States, followed by Towson, the county seat of Baltimore County, Maryland.
Some county seats may not be incorporated in their own right, but are located within incorporated municipalities. For example, Cape May Court House, New Jersey, though unincorporated, is a section of Middle Township, an incorporated municipality. In some of the colonial states, county seats include or included "Court House" as part of their name. In the Canadian provinces of Prince Edward Island, New Brunswick, Nova Scotia, the term "shire town" is used in place of county seat. County seats in Taiwan are the administrative centers of the counties. There are 13 county seats in Taiwan, which are in the forms of county-administered city, urban township or rural township. Most counties have only one county seat. However, some counties in Alabama, Georgia, Kentucky, Mississippi, New Hampshire, New York, Vermont have two or more county seats located on opposite sides of the county. An example is Harrison County, which lists both Biloxi and Gulfport as county seats; the practice of multiple county seat towns dates from the days.
There have been few efforts to eliminate the two-seat arrangement, since a county seat is a source of pride for the towns involved. There are 36 counties with multiple county seats in 11 states: Coffee County, Alabama St. Clair County, Alabama Arkansas County, Arkansas Carroll County, Arkansas Clay County, Arkansas Craighead County, Arkansas Franklin County, Arkansas Logan County, Arkansas Mississippi County, Arkansas Prairie County, Arkansas Sebastian County, Arkansas Yell County, Arkansas Columbia County, Georgia Lee County, Iowa Campbell County, Kentucky Kenton County, Kentucky Essex County, Massachusetts Middlesex County, Massachusetts Plymouth County, Massachusetts Bolivar County, Mississippi Carroll County, Mississippi Chickasaw County, Mississippi Harrison County, Mississippi Hinds County, Mississippi Jasper County, Mississippi Jones County, Mississippi Panola County, Mississippi Tallahatchie County, Mississippi Yalobusha County, Mississippi Jackson County, Missouri Hillsborough County, New Hampshire Seneca County, New York Bennington County, Vermont In New England, the town, not the county, is the primary division of local government.
Counties in this region have served as dividing lines for the states' judicial systems. Connecticut and Rhode Island have no county level of thus no county seats. In Vermont and Maine the county seats are designated shire towns. County government consists only of a Superior Court and Sheriff, both located in the respective shire town. Bennington County has two shire towns. In Massachusetts, most government functions which would otherwise be performed by county governments in other states are performed by town or city governments; as such, Massachusetts has dissolved many of its county governments, the state government now operates the registries of deeds and sheriff's offices in those counties. In Virginia, a county seat may be an independent city surrounded by, but not part of, the county of which it is the administrative center. Two counties in South Dakota have their county seat and government services centered in a neighboring county, their county-level services are provided by Fall River Tripp County, respectively.
In Louisiana, divided into parishes rather than counties, county seats are referred to as parish seats. Alaska is divided into boroughs rather than counties; the Unorganized Borough, which covers 49 % of Alaska's area, has equivalent. The state with the most counties is Texas, with 254, the state with the fewest counties is Delaware, with 3. County seat war Administrative center County town, administrative centres in Ireland and the UK Chef-lieu, administrative centres in Algeria, Luxembourg, France and Tunisia Municipality, equivalent to county in many c
San Luis Valley
The San Luis Valley is a region in south-central Colorado with a small portion overlapping into New Mexico. It is the headwaters of the Rio Grande, it contains 6 portions of 3 others. The San Luis Valley was ceded to the United States by Mexico following the Mexican–American War. Hispanic settlers began moving north and settling in the valley after the United States made a treaty with the Utes and established a fort. Prior to the Mexican war the Spanish and Mexican governments had reserved the valley to the Utes, their allies. During the 19th century Anglo settlers settled in the valley and engaged in mining and irrigated agriculture. Today the valley has a diverse Hispanic population, it is an extensive high-altitude depositional basin of 8,000 square miles with an average elevation of 7,664 feet above sea level. The valley is a section of the Rio Grande Rift and is drained to the south by the Rio Grande, which rises in the San Juan Mountains to the west of the valley and flows south into New Mexico.
The valley is 122 miles long and 74 miles wide, extending from the Continental Divide on the northwest rim into New Mexico on the south. The San Luis Valley has a cold desert climate but has substantial water resources from the Rio Grande and groundwater. Prior to 1868 the Capote band of Ute Indians lived in the valley; the Utes made a treaty of peace with the United States in 1849 shortly after the Mexican War. Shortly thereafter settlers from New Mexico established several small settlements in what is now Colorado and in 1868 the Utes were removed to a reservation in western Colorado, they continued to play a role in Saguache in the northwestern corner of the valley from the Los Pinos Agency to the west of Saguache until they lost their expansive reservation as the result of the Meeker Massacre in 1879. The area was administered as part of the Spanish Mexican, province of Nuevo Mexico until the area was ceded to the United States in 1848 after the Mexican–American War in the Treaty of Guadalupe Hidalgo.
Extensive settlement began in the Valley by Hispanic farmers and ranchers from New Mexico, in the 1850s after the construction of Fort Massachusetts by the U. S. Army for protection against the Utes, who barred settlers. Settlers built a church in the village, now called San Luis and dedicated it on the Feast of Saint Louis, June 21, 1851; the history of the post-war U. S. military presence in the Valley is preserved at Fort Garland and other sites in the Valley, which became part of the Territory of Colorado in 1861. The lands in the valley were surveyed by the United States using the New Mexico Meridian and Baseline, unlike the rest of Colorado; the valley was one of eight candidate sites to detonate the first atomic bomb when White Sands Proving Ground was selected for the Trinity. Today, the Valley has the largest native Hispanic population in Colorado; the original Ute population was confined to the Southern Ute and Ute Mountain Indian reservations in the late 19th century. The valley was the area.
The San Luis Valley is the broad flat, valley at the headwaters of the Rio Grande in south central Colorado and far north central New Mexico. The northern portion of the San Luis Valley is an endorheic basin. Irrigated agriculture is possible in the area due to groundwater and streams fed by the average 100 inches of snow the surrounding mountain ranges receive; the southern portion is drained by the Rio Grande. There is no clear southern boundary but the term is used to include the San Luis Hills of southern Colorado and the Taos Plateau of northern New Mexico. About 50 miles from east to west and about 150 miles from north to south, the valley is bounded on the east by the Sangre de Cristo Mountains and on the west by the San Juan Mountains. Within Colorado the San Luis Valley is considered to comprise six Colorado counties: Saguache, Rio Grande, Conejos and Mineral; the principal towns are: Alamosa, Monte Vista, Del Norte, South Fork, Saguache, Fort Garland, San Luis, Antonito, La Jara, Manassa, Crestone, Villa Grove, Mosca, San Acacio and a number of smaller locations.
A few other counties of Colorado have some land in the Rio Grande Basin including Archuleta County, Hinsdale County and San Juan County. Blanca Peak is prominent in the Sierra Blanca at the southern end of the northernmost section of the mountains, known as the Sangre de Cristo Range. There are several passes, with elevations between 9,000 and 10,000 feet, giving access to the valley. North La Veta Pass, through the Sangre de Cristo Mountains, is used by U. S. Highway 160 and by the San Luis and Rio Grande Railroad tracks. Other passes used were Medano and Sangre de Cristo Passes; the Great Sand Dunes are a famous feature of the valley. They lie directly to the west of the Sangre de Cristo Mountains; the dunes can reach 750 feet high. The Great Sand Dunes National Park and Preserve is now in place to protect both the dunes and the numerous archeological sites found in the area; the natural valley aquifer is close to the surface in this part of the valley, helps with maintenance of water levels in the San Luis Lakes, just to the west of the sand dunes.
Elevation rises as you go north in the valley to Poncha Pass, used now by U. S. Highway 285 and by the narrow gauge tracks of the Denver and Rio Grande Railroad. Otto Mears of Saguache and operated an historic toll road over Po