# Mississippi River *Principal river of the largest drainage basin in the United States, rising in northern Minnesota.* The Mississippi drains the largest river basin in the United States. After the Missouri, it is the country's second-longest river.[^1] It runs generally south for 2,340 miles (3,766 km) from Lake Itasca in northern [[Minnesota]], its traditional source, to its delta on the Gulf of Mexico. Its basin takes in all or part of 32 U.S. states and two Canadian provinces, though the main stem lies wholly inside the United States.[^1] Within Minnesota the river rises in Itasca State Park in [[Clearwater County, Minnesota]] and descends over the [[Falls of St. Anthony]] in [[Minneapolis]]. It flows past [[Saint Paul, Minnesota]] and through [[Lake Pepin]] on the Wisconsin line.[^1] On August 1, 2007, the I-35W Mississippi River bridge collapsed during the evening rush hour; the record lists 13 dead and 145 injured.[^2] The project's at-issue record names the river in two pairs. One concerns a deed describing land on the river's east bank, set beside the location of Carver County.[^3] The other sets a 2000 effluent reading from the [[Cottage Grove]] wastewater plant, which discharged to the river, beside the federal drinking-water limit for PFOA set in 2024.[^4][^5] ## Who Responsibility for keeping a navigation channel open rests with the United States Army Corps of Engineers, founded in 1802. Federal work on the channel dates from 1829, when crews began clearing snags, closing side channels and removing rock and sandbars.[^1] The [[National Park Service]] administers seven sites along the river. One of them, the Mississippi National River and Recreation Area, is devoted to the river itself.[^1] Private institutions also have records in the pack. The [[McKnight Foundation]] has published a notice on the sunset of its Mississippi River Program.[^6] It has also published a retrospective on that program.[^7] Friends of the Mississippi River publishes an account of itself as an organization.[^8] It also has an entry in ProPublica's Nonprofit Explorer.[^9] The Izaak Walton League, in the title of one of its own articles, describes the Upper Mississippi River National Wildlife and Fish Refuge as having been "Forged by the Izaak Walton League."[^10] The pack does not carry the text of these documents. ## What The name reaches English through French *Misi zipi*, a rendering of the Ojibwe *Misi-ziibi*, meaning "Great River."[^1] The upper river is an engineered channel. A chain of 29 locks and dams, most dating from the 1930s, exists chiefly to hold a channel 9 feet (2.7 m) deep for commercial barges. The dams are not intended to control floods. When flow is high, their gates are opened fully and the dams stop functioning.[^1] The record documents what that engineering has done to the river's sediment load. Before 1900 the river is estimated to have carried about 440 million short tons of sediment a year to coastal Louisiana and the Gulf. In the last two decades the figure has been about 160 million short tons a year. Wikipedia attributes the reduction to engineering on the Mississippi, Missouri and Ohio rivers and their tributaries. That work includes dams, meander cutoffs, river-training structures, bank revetments and soil-erosion control.[^1] On the lower river, salt water from the Gulf moves upstream along the bottom in dry years. It reached 64 miles (103 km) upriver in 2022. The Corps built underwater sand sills across the channel to hold it back in 1988, 1999, 2012 and 2022.[^1] ## When - About 200–500 AD: the Hopewell trade network operates along the basin's waterways.[^1] - About 600–1400 AD: Cahokia, the largest urban center of the Mississippian culture, is occupied. At its peak it had between 8,000 and 40,000 inhabitants.[^1] - September 29, 1837: by a [[Dakota]] cession, land east of the Mississippi is ceded, legally opening the site of Saint Paul.[^11] - 1855: the first bridge over the Mississippi is built in Minneapolis, at the location of the present Hennepin Avenue Bridge.[^1] - 1856: the first railroad bridge across the river is built.[^1] - June–July 1922: Ralph Samuelson of Lake City, Minnesota, develops water skiing on Lake Pepin. He makes the first water-ski jump in 1925.[^1] - 1930s: most of the upper river's 29 locks and dams are built.[^1] - August 1, 2007, 6:05 p.m.: the I-35W Mississippi River bridge collapses (NTSB investigation HWY07MH024).[^2] ## Where The river is customarily divided into three reaches.[^1] - The Upper Mississippi runs from the headwaters to the Missouri confluence at St. Louis. - The Middle Mississippi runs from the Missouri to the Ohio. - The Lower Mississippi runs from the Ohio to the Gulf. The upper reach has two parts. The headwaters run 493 miles (793 km) from the source to Saint Anthony Falls in Minneapolis. Below that, a navigable channel of human-made pools runs about 664 miles (1,069 km) from Minneapolis to St. Louis.[^1] Lake Itasca stands 1,475 feet (450 m) above sea level. Its name joins the end of the Latin *veritas* ("truth") to the start of *caput* ("head"). Smaller streams feed the lake.[^1] At Itasca the river is about 3 feet deep. Lake Pepin is the deepest stretch between Saint Paul and St. Louis, averaging 20–32 feet with a maximum of 60 feet.[^1] Ten states lie on or across the river, from Minnesota to Louisiana. Wisconsin, Illinois, Kentucky, Tennessee and Mississippi lie on the east bank. Iowa, Missouri and Arkansas lie on the west. Minnesota and Louisiana each extend across both banks.[^1] Interstate lines were fixed at the middle of the riverbed as it ran when each border was set. Where the channel has since moved, the lines stayed put, leaving small pieces of some states on the far side of the river.[^1] In Minnesota, [[Wright County, Minnesota]] has the river as a boundary. The county was established in 1855 and named for [[Silas Wright]].[^12] ## How many - Dams between Lake Itasca and St. Louis: 43. Fourteen stand above Minneapolis and serve uses including power generation and recreation. The other 29, starting in downtown Minneapolis, all have locks for navigation.[^1] - Fish species: about 375 in the basin, and about 120 in the Upper Mississippi alone.[^1] - Migratory birds: about 40% of U.S. migratory birds use the river corridor. Some 326 species, 60% of North America's migratory birds, use the basin as a flyway.[^1] - National Park Service sites along the river: seven.[^1] - I-35W bridge collapse, 2007: 13 dead, 145 injured.[^2] The Wikipedia source gives the basin's area as 1,151,000 square miles in its lead and "more than" 1,245,000 square miles in its watershed section. It ranks the river tenth in the world by discharge in one passage and fourteenth by volume in another.[^1] Measured from Brower's Spring in Montana, the source of the Missouri, the system's length is 3,710 miles (5,971 km), against 2,340 miles from Lake Itasca. The 2,340-mile figure is the one the United States Geological Survey uses.[^1] ## In the at-issue record **Carver County deed (pair AI-Carver-025).** The pair states that the deed described land on the east bank of the Mississippi. In its account, that land ran from the Falls of St. Anthony to Lake Pepin and extended five days' travel to the east. The pair states that Carver County lies west of the Mississippi on the [[Minnesota River]], and that the county is named after that deed. It names mnhs.org and wisconsinhistory.org as its sources. The pack carries no URL for either.[^3] **Cottage Grove effluent (pair AI-Washington-061).** The pair states that effluent from Cottage Grove's wastewater treatment plant showed PFOA at "an overall high of 1,991 micrograms per liter in early 2000." It states that the plant discharged to the Mississippi River for decades, and names the Minnesota Department of Health and the Federal Register among its sources.[^4] The federal drinking-water limit for PFOA, set in 2024, is 4.0 nanograms per liter.[^5] The pack does not name the plant's operator or the industrial sources of the PFOA. ## In the Minnesota record ### Where - Source: Lake Itasca, Itasca State Park, Clearwater County.[^1] - End of the headwaters reach: Saint Anthony Falls, Minneapolis.[^1] - Deepest stretch above St. Louis: Lake Pepin, on the Minnesota–Wisconsin line.[^1] - County boundary: Wright County.[^12] ### When - September 29, 1837: Dakota cession of land east of the Mississippi.[^11] - 1855: first bridge over the river, in Minneapolis.[^1] - August 1, 2007: I-35W Mississippi River bridge collapse.[^2] ## Notes [^1]: Wikipedia, *Mississippi River* (revision 1379869348, retrieved 2026-10-27) — course, length, basin, divisions, dams and locks, sediment, salt sills, boundaries, depth, history, recreation and ecology. https://en.wikipedia.org/wiki/Mississippi_River [^2]: National Transportation Safety Board, *Investigation HWY07MH024* — I-35W Mississippi River bridge collapse, August 1, 2007, 6:05 p.m.; 13 dead, 145 injured (as recorded in Minnesota Time Table row TL-0763). https://www.ntsb.gov/investigations/Pages/HWY07MH024.aspx [^3]: Minnesota wiki, *At-issue record*, pair AI-Carver-025 (sources named in the pair: mnhs.org, wisconsinhistory.org; no source URL in the pack) — bounds described in the deed; location of Carver County. [^4]: Minnesota wiki, *At-issue record*, pair AI-Washington-061 (sources named in the pair: health.state.mn.us, federalregister.gov; no source URL in the pack) — 2000 PFOA effluent reading at the Cottage Grove plant; discharge to the Mississippi. [^5]: U.S. Environmental Protection Agency, *Per- and Polyfluoroalkyl Substances (PFAS)* (Safe Drinking Water Act) — the federal drinking-water standard for PFOA. https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas [^6]: McKnight Foundation, *McKnight River Program to Sunset* (undated in the pack) — sunset of the foundation's Mississippi River Program. https://www.mcknight.org/news-ideas/mcknight-river-program-to-sunset/ [^7]: McKnight Foundation, *Honoring McKnight's Mississippi River Program* (undated in the pack) — the foundation's retrospective on the program. https://www.mcknight.org/news-ideas/honoring-mcknights-mississippi-river-program/ [^8]: Friends of the Mississippi River, *About Friends of the Mississippi River* — the organization's description of itself. https://fmr.org/about-friends-mississippi-river [^9]: ProPublica, *Nonprofit Explorer: Friends of the Mississippi River* — organization record 411763226. https://projects.propublica.org/nonprofits/organizations/411763226 [^10]: Izaak Walton League of America, *The Upper Mississippi River National Wildlife and Fish Refuge: Forged by the Izaak Walton League* — the League's account of its role in the refuge. https://iwla.org/the-upper-mississippi-river-national-wildlife-and-fish-refuge-forged-by-the-izaak-walton-league/ [^11]: Minnesota wiki, *Ramsey County history table*, row HE-0005 (no source URL in the pack) — Dakota cession of land east of the Mississippi, September 29, 1837. [^12]: Wikipedia, *Wright County, Minnesota* (dossier grade B; citing Warren Upham, *Minnesota Geographic Names*, 1920, and the U.S. Census) — Mississippi River boundary; established 1855; named for Silas Wright. https://en.wikipedia.org/wiki/Wright_County,_Minnesota