1.
Galena, Illinois
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Galena is the largest city in and the county seat of Jo Daviess County, Illinois, with a population of 3,429 at the 2010 census. A 581-acre section of the city is listed on the National Register of Historic Places as the Galena Historic District and it is named for the mineral galena, which was mined by Native Americans in the area for over a thousand years. Owing to these deposits, Galena was the site of the first major mineral rush in the United States, the first American settler arrived in 1821, and by 1828, the population was estimated at 10,000, rivaling the population of Chicago at the time. The city emerged as the largest steamboat hub on the Mississippi River north of St. Louis, Galena was the home of Ulysses S. Grant and eight other Civil War generals. Today, the city is a tourist destination known for its history, architecture, the city is named for galena, the natural form of lead sulfide and the most important lead ore. Native Americans mined the ore for use in burial rituals, the Havana Hopewell first traded galena in the area during the Middle Woodland period. However, the use of galena in the Havana territory is uncertain, during the Mississippian period, galena saw use as body paint. The French, probably via contact with the Sioux, first noted lead deposits in the Upper Mississippi Valley in 1658, a 1703 French map identified the northwestern Illinois area as mines de plumb. Northwestern Illinois was inhabited by Sac and Fox when the French arrived, in the 1690s, French trappers discovered the area and began mining the lead. However, conflicts with the Sioux prevented large-scale mining until Julien Dubuques Mines opened across the river in 1788, the French called Galena La Pointe and early Americans adopted this name as The Point. Early documentation officially records the name as Fever River, a name for the Galena River. George Davenport, a colonel in the United States Army. Three years later, Jesse W. Shull built a trading post, january family, who arrived in 1821 from Maysville, Kentucky, are considered the first permanent American settlers. The next year, the US Department of War assumed control of the mines, a large group of colonists led by Dr. Moses Meeker and James Harris arrived in 1823. The first official lease of the mines on behalf of the US government was to James Johnson, martin Thomas, appointed by the government in 1824 to oversee mine leases, was commissioned to survey the mines in 1826. The name Galena was purportedly given during a meeting that year, rejected names included Jackson, Harrison. Thomas platted the town and, starting in June 1827, settlers could lease plots from the government, the land remained in government possession until the leasing system was eased out in 1836–37. When Jo Daviess County was founded in 1827, Galena was named its county seat and this established the first courts in Galena, previous legal proceedings were heard in front of the Superintendent of Lead Mines
2.
Floodgate
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Floodgates, also called stop gates, are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, since most of these devices operate by controlling the water surface elevation being stored or routed, they are also known as crest gates. Valves used in applications have a variety of design requirements and are usually located at the base of dams. Often, the most important requirement is energy dissipation, since water is very heavy, it exits the base of a dam with the enormous force of water pushing from above. Unless this energy is dissipated, the flow can erode nearby rock and soil, other design requirements include taking into account pressure head operation, the flow rate, whether the valve operates above or below water, and the regulation of precision and cost. Fixed cone valves are designed to dissipate the energy from a water flow during reservoir discharge and they are a round pipe section with an adjustable sleeve gate and cone at the discharge end. Flow is varied by moving the sleeve away or towards its cone seat, the design allows high pressure water from the base of a dam to be released without causing erosion to the surrounding environment. Fixed cone valves are able to handle heads up to 300 m, hollow jet valves are a type of needle valve used for floodgate discharge. A cone and seat are inside a pipe, water flows through an annular gap between the pipe and cone when it is moved downstream, away from the seat. Ribs support the assembly and supply air for water jet stabilization. Ring jet valves are similar to fixed cone valves, but have a collar that discharges water in a narrow stream. They are suitable for heads up to 50 m, jet flow gate, similar to a gate valve but with a conical restriction prior to the gate leaf that focuses the water into a jet. They were developed in the 1940s by the United States Bureau of Reclamation to allow control of discharge flow without the cavitation seen in regular gate valves. Jet flow gates are able to handle heads up to 150 m, tidal barrage Canal lock Thames Barrier Delta Works Oosterscheldekering US Army Corps of Engineers. Engineering manual 1110-2-2607, Planning and Design of Navigation Dams, Chapter 5, deltaWorks. Org – project in the Netherlands on floodgates
3.
Levee
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A levee, dike, dyke, embankment, floodbank or stopbank is an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels. It is usually earthen and often parallel to the course of a river in its floodplain or along low-lying coastlines, the word levee, from the French word levée, is used in American English. It originated in New Orleans a few years after the founding in 1718 and was later adopted by English speakers. The name derives from the trait of the ridges being raised higher than both the channel and the surrounding floodplains. The modern word dike or dyke most likely derives from the Dutch word dijk, the 126 kilometres long Westfriese Omringdijk was completed by 1250, and was formed by connecting existing older dikes. The Roman chronicler Tacitus even mentions that the rebellious Batavi pierced dikes to flood their land, the word dijk originally indicated both the trench and the bank. It is closely related to the English verb to dig, in Anglo-Saxon, the word dic already existed and was pronounced as dick in northern England and as ditch in the south. Similar to Dutch, the English origins of the lie in digging a trench. This practice has meant that the name may be given to either the excavation or the bank, thus Offas Dyke is a combined structure and Car Dyke is a trench though it once had raised banks as well. In the midlands and north of England, and in the United States, a dike is what a ditch is in the south, a property boundary marker or small drainage channel. Where it carries a stream, it may be called a dike as in Rippingale Running Dike. The Weir Dike is a dike in Bourne North Fen, near Twenty and alongside the River Glen. In the Norfolk and Suffolk Broads, a dyke may be a ditch or a narrow artificial channel off a river or broad for access or mooring, some longer dykes being named. In parts of Britain, particularly Scotland, a dyke may be a field wall, Levees can be mainly found along the sea, where dunes are not strong enough, along rivers for protection against high-floods, along lakes or along polders. Furthermore, levees have been built for the purpose of empoldering, the latter can be a controlled inundation by the military or a measure to prevent inundation of a larger area surrounded by levees. Levees have also built as field boundaries and as military defences. More on this type of levee can be found in the article on dry-stone walls, Levees can be permanent earthworks or emergency constructions built hastily in a flood emergency. When such a bank is added on top of an existing levee it is known as a cradge
4.
Confluence
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In geography, a confluence is the meeting of two or more bodies of water. The term is used to describe the meeting of tidal or other non-riverine bodies of water. A one-mile portion of the Industrial Canal in New Orleans accommodates the Gulf Intracoastal Waterway, niagara-on-the-Lake, Ontario, Canada is at the confluence of the Niagara River and Lake Ontario. The junction of the Green River and Colorado River forms the heart of Canyonlands National Park in Utahs Canyon Country, the Sangam, near Allahabad, India, where the sacred rivers Ganges and Yamuna meet to create one of the holiest places in Hinduism. The Ohio River is formed by the confluence of the Monongahela and Allegheny rivers, located in Pittsburgh, the Madison, Jefferson and Gallatin Rivers in Three Forks, Montana form the confluence of the Missouri River, one of the longest rivers in the United States. Kuala Lumpur, the capital of Malaysia, is at the confluence of the Gombak River and the Klang River. Passau known also as the Dreiflüssestadt, because the Danube River is joined there by the Inn River from the South, manaus, Brazil is on the Rio Negro near its confluence with the Amazon. It is the port and a hub for the regions extensive river system. Osijek, Croatia, is on the bank of the river Drava 25 km upstream of its confluence with the Danube. Belgrade, the capital of Serbia lies at the confluence of the Sava, the Hochelaga Archipelago, including the island and city of Montreal, is located at the confluence of the St. Lawrence River and Ottawa River in Quebec, Canada. Winnipeg, Canada, is at the confluence of the Red River, the area is referred to as The Forks by locals, and has been an important trade location for over 6000 years. The confluence of the rivers Danube and Morava in Devín on the border between Slovakia and Austria, triangle of Three Emperors, former tripoint in Europe. Cairo, Illinois, in the United States, where the Ohio River flows into the Mississippi River, St. Louis, Missouri, is built just south of the confluence of the Mississippi River and the Missouri River. Lyon, France is located on the confluence of the Saône and Rhone rivers, lytton, British Columbia, Canada, is located at the confluence of the muddy Fraser River and the clearer Thompson River. The confluence between the Franklin River and Gordon River in south-western Tasmania The confluence of the Snake and Columbia River at the Tri-Cities of Washington, the confluence of the rivers Pivka and Rak is one of the largest subterranean confluences in Europe. The confluence at Lokoja, Nigeria, where the Niger and Benue rivers merge, the Sudanese capital of Khartoum, located at the confluence of the White Nile and the Blue Nile. This merging point is the beginning of the Nile, columbus, Ohio, in the United States is at the confluence of the Scioto and Olentangy rivers. Luang Prabang in Laos is at the confluence of the Mekong, River Kabul and River Swat at Attock, in Pakistan
5.
River
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A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water, small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the term river as applied to geographic features. Many names for small rivers are specific to geographic location, examples are run in parts of the United States, burn in Scotland and northeast England. Sometimes a river is defined as being larger than a creek, but not always, Rivers are part of the hydrological cycle. Potamology is the study of rivers while limnology is the study of inland waters in general. Extraterrestrial rivers of liquid hydrocarbons have recently found on Titan. Channels may indicate past rivers on other planets, specifically outflow channels on Mars and rivers are theorised to exist on planets, a river begins at a source, follows a path called a course, and ends at a mouth or mouths. The water in a river is confined to a channel. In larger rivers there is also a wider floodplain shaped by flood-waters over-topping the channel. Floodplains may be wide in relation to the size of the river channel. This distinction between river channel and floodplain can be blurred, especially in areas where the floodplain of a river channel can become greatly developed by housing. Rivers can flow down mountains, through valleys or along plains, the term upriver refers to the direction towards the source of the river, i. e. against the direction of flow. Likewise, the term describes the direction towards the mouth of the river. The term left bank refers to the bank in the direction of flow. The river channel typically contains a stream of water, but some rivers flow as several interconnecting streams of water. Extensive braided rivers are now found in only a few regions worldwide and they also occur on peneplains and some of the larger river deltas. Anastamosing rivers are similar to braided rivers and are quite rare
6.
Midwestern United States
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It was officially named the North Central region by the Census Bureau until 1984. Illinois is the most populous of the states and North Dakota the least, a 2012 report from the United States Census put the population of the Midwest at 65,377,684. The Midwest is divided by the Census Bureau into two divisions, the East North Central Division includes Illinois, Indiana, Michigan, Ohio and Wisconsin, all of which are also part of the Great Lakes region. Major rivers in the include, from east to west, the Ohio River, the Upper Mississippi River. Chicago is the most populated city in the American Midwest and the third most populous in the entire country, other large Midwest cities include, Indianapolis, Columbus, Detroit, Milwaukee, Kansas City, Omaha, Minneapolis, Cleveland, Wichita and St. Louis. Chicago and its suburbs form the largest metropolitan area with 9.8 million people, followed by Metro Detroit. Paul, Greater St. Louis, Greater Cleveland, Greater Cincinnati, Kansas City metro area, the term Midwestern has been in use since the 1880s to refer to portions of the central United States. A variant term, Middle West, has used since the 19th century. Another term sometimes applied to the general region is the heartland. Other designations for the region have fallen out of use, such as the Northwest or Old Northwest, the Northwest Territory was one of the earliest territories of the United States, stretching northwest from the Ohio River to northern Minnesota and upper-Mississippi. The upper-Mississippi watershed including the Missouri and Illinois Rivers was the setting for the earlier French settlements of the Illinois Country, economically the region is balanced between heavy industry and agriculture, with finance and services such as medicine and education becoming increasingly important. Its central location makes it a crossroads for river boats, railroads, autos, trucks. Politically the region swings back and forth between the parties, and thus is heavily contested and often decisive in elections, after the sociological study Middletown, which was based on Muncie, Indiana, commentators used Midwestern cities as typical of the nation. The region has a higher ratio than the Northeast, the West. Traditional definitions of the Midwest include the Northwest Ordinance Old Northwest states, the states of the Old Northwest are also known as Great Lakes states and are east-north central in the United States. The Ohio River runs along the section while the Mississippi River runs north to south near the center. Many of the Louisiana Purchase states in the west-north central United States, are known as Great Plains states. The Midwest lies north of the 36°30′ parallel that the 1820 Missouri Compromise established as the line between future slave and non-slave states
7.
Illinois
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Illinois is a state in the midwestern region of the United States, achieving statehood in 1818. It is the 6th most populous state and 25th largest state in terms of land area, the word Illinois comes from a French rendering of a native Algonquin word. For decades, OHare International Airport has been ranked as one of the worlds busiest airports, Illinois has long had a reputation as a bellwether both in social and cultural terms and politics. With the War of 1812 Illinois growth slowed as both Native Americans and Canadian forces often raided the American Frontier, mineral finds and timber stands also had spurred immigration—by the 1810s, the Eastern U. S. Railroads arose and matured in the 1840s, and soon carried immigrants to new homes in Illinois, as well as being a resource to ship their commodity crops out to markets. Railroads freed most of the land of Illinois and other states from the tyranny of water transport. By 1900, the growth of jobs in the northern cities and coal mining in the central and southern areas attracted a new group of immigrants. Illinois was an important manufacturing center during both world wars, the Great Migration from the South established a large community of African Americans in Chicago, who created the citys famous jazz and blues cultures. Three U. S. presidents have been elected while living in Illinois, Abraham Lincoln, Ulysses S. Grant, additionally, Ronald Reagan, whose political career was based in California, was the only U. S. president born and raised in Illinois. Today, Illinois honors Lincoln with its official slogan, Land of Lincoln. The Abraham Lincoln Presidential Library and Museum is located in the capital of Springfield. Illinois is the spelling for the early French Catholic missionaries and explorers name for the Illinois Native Americans. American scholars previously thought the name Illinois meant man or men in the Miami-Illinois language and this etymology is not supported by the Illinois language, as the word for man is ireniwa and plural men is ireniwaki. The name Illiniwek has also said to mean tribe of superior men. The name Illinois derives from the Miami-Illinois verb irenwe·wa he speaks the regular way and this was taken into the Ojibwe language, perhaps in the Ottawa dialect, and modified into ilinwe·. The French borrowed these forms, changing the ending to spell it as -ois. The current spelling form, Illinois, began to appear in the early 1670s, the Illinois name for themselves, as attested in all three of the French missionary-period dictionaries of Illinois, was Inoka, of unknown meaning and unrelated to the other terms. American Indians of successive cultures lived along the waterways of the Illinois area for thousands of years before the arrival of Europeans, the Koster Site has been excavated and demonstrates 7,000 years of continuous habitation
8.
Upper Mississippi River
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The Upper Mississippi River is the portion of the Mississippi River upstream of Cairo, Illinois, United States. From the headwaters at Lake Itasca, Minnesota, the flows approximately 2000 kilometers to Cairo. The collapse of ice dams holding back Glacial Lake Duluth and Glacial Lake Grantsburg carved out the Dalles of the St. Croix River, the Upper Mississippi River valley likely originated as an ice-marginal stream during what had been referred to as the “Nebraskan” glaciation. Current terminology would place this as Pre-Illinoian Stage, the Driftless Area is a portion of North America left unglaciated at that ice ages height, hence not smoothed out or covered over by previous geological processes. Considering the history of Glacial Lake Missoula, something like this is believed to have happened, the Upper Mississippi from below St. Anthony Falls downstream to St. Paul, Minnesota is a gorge with high limestone bluffs carved by the waterfall. Upstream of the waterfall the land slopes gently to rivers edge, downstream of downtown St. Paul the river enters its wide preglacial valley. The states of Minnesota, Wisconsin and Iowa, along with the government, have preserved certain areas of the land along this reach of the river. There are three National Park Service sites along the Upper Mississippi River, the Mississippi National River and Recreation Area is the National Park Service site dedicated to protecting and interpreting the Mississippi River itself. The other two National Park Service sites along the river are, Effigy Mounds National Monument and the Jefferson National Expansion Memorial, unlike the Lower Mississippi, much of the upper river is a series of pools created by a system of 29 locks and dams. The structures were authorized by Congress in the 1930s, and most were completed by 1940, a primary reason for damming the river is to facilitate barge transportation. The dams regulate water levels for the Upper River and play a part in regulating levels on the Lower Mississippi. On the upper reaches near the Minnesota-Wisconsin border, the floodplain is between 1.5 and 5 kilometers wide. South of St. Louis, Missouri, the floodplain is approximately 80 kilometers wide. Major tributaries to the Upper Mississippi River include the Missouri, Illinois, Minnesota, St. Croix, Black, the Upper Mississippi provides habitat for more than 125 fish species and 30 species of freshwater mussels. Three national wildlife refuges along the river cover a total of 465 square kilometers, the largest of them, the Upper Mississippi River National Wildlife and Fish Refuge, is over 420 kilometers long, reaching from the Alma, Wisconsin area down to Rock Island, Illinois. The refuge consists of blufflands, marshes, bottomland forest, islands, channels, backwater lakes and it is part of the Mississippi Flyway. Although the river is cleaner than it was in recent decades. The five states bordering the Upper Mississippi River are working together to water quality issues
9.
Winnebago War
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Not quite a war, the hostilities were limited to a few attacks on American civilians by a portion of the Winnebago Native American tribe. The Ho-Chunks were reacting to a wave of lead miners trespassing on their lands, most Native Americans in the region decided against joining the uprising, and so the conflict ended after U. S. officials responded with a show of military force. Ho-Chunk chiefs surrendered eight men who had participated in the violence, including Red Bird, Red Bird died in prison in 1828 while awaiting trial, two other men convicted of murder were pardoned by President John Quincy Adams and released. As a result of the war, the Ho-Chunk tribe was compelled to cede the lead mining region to the United States, the Americans also increased their military presence on the frontier, building Fort Winnebago and reoccupying two other abandoned forts. The conflict convinced some officials that Americans and Indians could not live together, and that the Natives should be compelled to move westward. The Winnebago War preceded the larger Black Hawk War of 1832, following the War of 1812, the United States pursued a policy of trying to prevent wars among Native Americans in the Upper Mississippi River region. On August 19,1825, U. S. officials finalized a treaty at Prairie du Chien. By that time, however, white Americans had begun to trespass on Ho-Chunk lands in large numbers, Native Americans had mined this region for thousands of years, and exporting lead had become an important part of the Ho-Chunk economy. Ho-Chunks tried to drive away the trespassers, but they often suffered abuse at the hands of aggressive miners. Some U. S. officials, concerned that Ho-Chunk mining would delay what they saw as the inevitable American possession of the mining region, the murderers evidently had no specific grievance with the victims, who were targets of opportunity. Two Ho-Chunk suspects were arrested by Prairie du Chien militiamen and taken to Fort Crawford, after they escaped, U. S. Army Lieutenant Colonel Willoughby Morgan seized two Ho-Chunk hostages and demanded that the Ho-Chunk tribe turn over the murderers. On July 4,1826, the Ho-Chunks delivered six men to Morgan at Fort Crawford, the Americans, however, wanted to punish those personally responsible for the killings. Colonel Morgan was unable to determine who was guilty, and so he detained all six, Colonel Josiah Snelling, commander of the 5th Infantry Regiment, reinforced the fort amid rumors that the Ho-Chunks were going to attempt to free the prisoners. Eventually, two Ho-Chunks, Wau-koo-kau and Man-ne-tah-peh-keh, were turned over to the Americans and indicted for the murders, the two Ho-Chunk prisoners were also moved to Fort Snelling. In May 1827, after Dakotas attacked an Ojibwe party near Fort Snelling, Colonel Snelling arrested four of the Dakotas and turned them over to the Ojibwes, who killed them. This angered some Dakotas, who encouraged the Ho-Chunks to help them strike at the Americans, the false story of the execution of the Ho-Chunk prisoners, along with the incessant American trespassing, convinced some Ho-Chunks to take up arms against the United States. The timing seemed right, since the evacuation of Fort Crawford appeared to be a sign of American weakness, the Ho-Chunks broke off diplomatic relations with the United States by not showing up for a scheduled treaty conference, and prepared for war. In late June 1827, a Ho-Chunk leader named Red Bird, along with Wekau and Chickhonsic, unable to locate their intended victim, they instead targeted the cabin of Registre Gagnier, the son of an esteemed African-American nurse and midwife named Aunt Mary Ann
10.
Shullsburg, Wisconsin
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Shullsburg is a city in Lafayette County, Wisconsin, United States. The population was 1,226 at the 2010 census, the city is located within the Town of Shullsburg. According to the United States Census Bureau, the city has an area of 1.11 square miles. As of the census of 2010, there were 1,226 people,534 households, the population density was 1,106 people per square mile. There were 549 housing units at a density of 499 per square mile. The racial makeup of the city was 99. 1% White,0. 2% Asian,35. 4% of all households were made up of individuals. The average household size was 2.3 and the family size was 2.96. In the city, the population was out with 24. 4% under the age of 18,7. 9% from 18 to 24,21. 5% from 25 to 44,29. 8% from 45 to 64. The median age was 43.3 years, for every 100 females there were 94.9 males. For every 100 females age 18 and over, there were 92.7 males, Shullsburg was the boyhood home of Lou Blonger, the Bunco King of Denver, Colorado. Blonger lived in Shullsburg from 1853, when he was four, until 1864, Shullsburg was the birthplace of George Safford Parker, founder of Parker Pen Company. Representative Henry S. Magoon practiced law in Shullsburg, Senator from Missouri William Warner was born in Shullsburg. Wisconsin State Assemblyman Joseph E. Tregoning was born in Shullsburg, actor Howard Kyle was born in Shullsburg. Father was the first commander of the Shullsburg Light Guard Baseball player Johnny Gerlach was born in Shullsburg, Wisconsin State Senator James Earnest lived in Shullsburg. Wisconsin State Assemblyman James H. Knowlton lived in Shullsburg, Wisconsin State Senator Philemon Simpson lived in Shullsburg. Wisconsin State Assemblyman Calvert Spensley lived in Shullsburg, Wisconsin State Assemblyman John K. Williams lived in Shullsburg. Wisconsin State Assemblyman James W. Freeman lived in Shullsburg, Henry Gratiot City of Shullsburg, Wisconsin Sanborn fire insurance maps,1894190019081915
11.
Mississippi River
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The Mississippi River is the chief river of the largest drainage system on the North American continent. Flowing entirely in the United States, it rises in northern Minnesota, with its many tributaries, the Mississippis watershed drains all or parts of 31 U. S. states and 2 Canadian provinces between the Rocky and Appalachian Mountains. The Mississippi ranks as the fourth longest and fifteenth largest river in the world by discharge, the river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. Native Americans long lived along the Mississippi River and its tributaries, most were hunter-gatherers, but some, such as the Mound Builders, formed prolific agricultural societies. The arrival of Europeans in the 16th century changed the way of life as first explorers, then settlers. The river served first as a barrier, forming borders for New Spain, New France, and the early United States, and then as a vital transportation artery and communications link. Formed from thick layers of the silt deposits, the Mississippi embayment is one of the most fertile agricultural regions of the country. In recent years, the river has shown a shift towards the Atchafalaya River channel in the Delta. The word itself comes from Messipi, the French rendering of the Anishinaabe name for the river, see below in the History section for additional information. In addition to historical traditions shown by names, there are at least two measures of a rivers identity, one being the largest branch, and the other being the longest branch. Using the largest-branch criterion, the Ohio would be the branch of the Lower Mississippi. Using the longest-branch criterion, the Middle Mississippi-Missouri-Jefferson-Beaverhead-Red Rock-Hellroaring Creek River would be the main branch and its length of at least 3,745 mi is exceeded only by the Nile, the Amazon, and perhaps the Yangtze River among the longest rivers in the world. The source of this waterway is at Browers Spring,8,800 feet above sea level in southwestern Montana and this is exemplified by the Gateway Arch in St. Louis and the phrase Trans-Mississippi as used in the name of the Trans-Mississippi Exposition. It is common to qualify a regionally superlative landmark in relation to it, the New Madrid Seismic Zone along the river is also noteworthy. These various basic geographical aspects of the river in turn underlie its human history and present uses of the waterway, the Upper Mississippi runs from its headwaters to its confluence with the Missouri River at St. Louis, Missouri. The source of the Upper Mississippi branch is traditionally accepted as Lake Itasca,1,475 feet above sea level in Itasca State Park in Clearwater County, however, the lake is in turn fed by a number of smaller streams. From its origin at Lake Itasca to St. Louis, Missouri, fourteen of these dams are located above Minneapolis in the headwaters region and serve multiple purposes, including power generation and recreation. The remaining 29 dams, beginning in downtown Minneapolis, all locks and were constructed to improve commercial navigation of the upper river
12.
Driftless Area
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The Driftless Area or Paleozoic Plateau is a region in the American Midwest noted mainly for its deeply carved river valleys. While primarily in southwestern Wisconsin, it includes areas of southeastern Minnesota, northeastern Iowa, the region includes elevations ranging from 603 to 1,719 feet at Blue Mound State Park and covers an area of 16,203 square miles. The regions peculiar terrain is the result of its having escaped glaciation in the last glacial period, retreating glaciers leave behind silt, clay, sand, gravel, and boulders called drift. The northern and eastern lobes were in part diverted around the area by the Watersmeet Dome, the Green Bay and Lake Michigan lobes were also partially blocked by the bedrock of the Door Peninsula, which presently separates Green Bay from Lake Michigan. In earlier phases of the Wisconsinan, the Driftless Area was totally surrounded by ice, in the adjacent glaciated regions, the glacial retreat left behind drift, which buried all former topographical features. Surface water was forced to carve out new stream beds, overall, the region is characterized by an eroded plateau with bedrock overlain by varying thicknesses of loess. Most characteristically, the valleys are deeply dissected. The bluffs lining this reach of the Mississippi River currently climb to nearly 600 feet, in Minnesota, Pre-Illinoian-age till was probably removed by natural means prior to the deposition of loess. The sedimentary rocks of the walls date to the Paleozoic Era and are often covered with colluvium or loess. In the east, the Baraboo Range, an ancient, profoundly eroded monadnock, the area has not undergone much tectonic action, as all the visible layers of sedimentary rock are approximately horizontal. Karst topography is found throughout the Driftless area and this is characterized by caves and cave systems, disappearing streams, blind valleys, underground streams, sinkholes, springs, and cold streams. Disappearing streams occur where surface waters sinks down into the earth through fractured bedrock or a sinkhole, either joining an aquifer, blind valleys are formed by disappearing streams and lack an outlet to any other stream. Sinkholes are the result of the collapse of the roof of a cave, disappearing streams can re-emerge as large cold springs. Cold streams with cold springs as their sources are noted as superb trout habitat, the Mississippi River passes through the Driftless Area between and including Pool 2 and Pool 13. As rivers and streams approach their confluence with the Mississippi, their canyons grow progressively steeper and deeper, the change in elevation above sea level from ridgetops lining a stream to its confluence with the Big River can reach well past 650 feet in only a few miles. The Waukon Municipal Airport is reliably established as being 1,281 feet above sea level, the Army Corps of Engineers maintains a river level in Pool 9 of about 619 feet above sea level, which covers Lansing. Maps and signs issued by the Iowa Department of Transportation indicate Waukon and this is a drop of more than 660 feet in less than 20 miles. The role of isostatic rebound on the process of stream incision in the area is not clearly understood, there are many small towns in the Driftless Area, especially in river valleys, at or upstream from the Mississippi
