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119-813: The Yamhill River is an 11-mile (18 km) tributary of the Willamette River , in the U.S. state of Oregon . Formed by the confluence of the South Yamhill River and the North Yamhill River about 3 miles (5 km) east of McMinnville , it drains part of the Northern Oregon Coast Range . The river meanders east past Dayton to join the Willamette River at its river mile (RM) 55 or river kilometer (RK) 89, south of Newberg . It

238-562: A flood in 1861 . This and many other large flows preceded the Flood Control Act of 1936 and dam construction on the Willamette's major tributaries. The river below Willamette Falls, 26.5 miles (42.6 km) from the mouth, is affected by semidiurnal tides , and gauges have detected reverse flows (backwards river flows) below Ross Island at RM 15 (RK 24). The National Weather Service issues tide forecasts for

357-569: A Corps of Engineers ... that the said Corps ... shall be stationed at West Point in the State of New York and shall constitute a military academy." Until 1866, the superintendent of the United States Military Academy was always an Engineer Officer. The General Survey Act of 1824 authorized the use of Army engineers to survey road and canal routes for the growing nation. That same year, Congress passed an "Act to Improve

476-469: A doctrinal framework for employing capabilities; and remaining an adaptive institution in order to provide Commanders with the freedom of action they need to successfully execute Unified Land Operations. There are several other organizations within the Corps of Engineers: USACE provides support directly and indirectly to the warfighting effort. They build and help maintain much of the infrastructure that

595-463: A hand-selected unit of volunteer Army combat engineers trained in jungle warfare, knife fighting, and unarmed jujitsu ( hand-to-hand combat ) techniques. Working in camouflage, the Pioneers cleared jungle, prepared routes of advance and established bridgeheads for the infantry, as well as demolishing enemy installations. Five commanding generals (chiefs of staff after the 1903 reorganization) of

714-454: A major provider of hydroelectric energy and the country's leading provider of recreation, Its role in responding to natural disasters also grew dramatically, especially following the devastating Mississippi Flood of 1927 . In the late 1960s, the agency became a leading environmental preservation and restoration agency. In 1944, specially trained army combat engineers were assigned to blow up underwater obstacles and clear defended ports during

833-506: A new emphasis on a more holistic approach to risk management. As part of this work, USACE is the number one provider of outdoor recreation in the U.S., so there is a significant emphasis on water safety. Army involvement in works "of a civil nature," including water resources, goes back almost to the origins of the U.S. Over the years, as the nation's needs have changed, so have the Army's Civil Works missions. Major areas of emphasis include

952-418: A plan to improve fish passage and take other actions to help native fish recover in 2008. Since then, work has proceeded slowly, and the Corps of Engineers, citing engineering difficulties and cost, may not meet the original agreed-upon deadline of 2023 for a system of effective remedies. Other major dams in the Willamette watershed are owned by other interests; for example, several hydroelectric facilities on

1071-404: A power plant. The locks at Willamette Falls were completed in 1873. Elsewhere on the main stem, numerous minor flow-regulation structures force the river into a narrower and deeper channel to facilitate navigation and flood control . The dams on the Willamette's major tributaries are primarily large flood-control, water-storage, and power-generating dams. Thirteen of these dams were built from

1190-523: A system of parks, trails, and wildlife refuges along the river. In 1998, the Willamette became one of 14 rivers designated an American Heritage River by U.S. President Bill Clinton . By 2007 the Greenway had grown to include more than 170 separate land parcels, including 10 state parks. Public uses of the river and land along its shores include camping, swimming, fishing, boating, hiking, bicycling, and wildlife viewing. In 2008, government agencies and

1309-467: A temporary lake, Lake Allison , that stretched from Lake Oswego to near Eugene. The ancestral Tualatin Valley, part of the Willamette basin, flooded as well; water depths ranged from 200 feet (61 m) at Lake Oswego to 100 feet (30 m) as far upstream (west) as Forest Grove . Flood deposits of silt and clay, ranging in thickness from 115 feet (35 m) in the north to about 15 feet (4.6 m) in

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1428-578: A typical year, the Corps of Engineers responds to more than 30 Presidential disaster declarations, plus numerous state and local emergencies. Emergency responses usually involve cooperation with other military elements and Federal agencies in support of State and local efforts. Work comprises engineering and management support to military installations, global real estate support, civil works support (including risk and priorities), operations and maintenance of Federal navigation and flood control projects, and monitoring of dams and levees. More than 67 percent of

1547-434: A week. The battalion also deployed in support of post-Katrina operations. All of this work represents a significant investment in the nation's resources. Through its Civil Works program, USACE carries out a wide array of projects that provide coastal protection, flood protection, hydropower, navigable waters and ports, recreational opportunities, and water supply. Work includes coastal protection and restoration, including

1666-400: Is Portland, with more than 500,000 residents. Not all of these cities draw water in part or exclusively from the Willamette for their municipal water supply. Other cities in the watershed (but not on the main-stem river) with populations of 20,000 or more are Gresham, Hillsboro, Beaverton, Tigard, McMinnville, Tualatin, Woodburn , and Forest Grove. Sixty-four percent of the watershed

1785-512: Is from Albany to Oregon City. At Willamette Falls , between West Linn and Oregon City, the river plunges about 40 feet (12 m). For the rest of its course, the river is extremely low-gradient and is affected by Pacific Ocean tidal effects from the Columbia. The main stem of the Willamette varies in width from about 330 to 660 feet (100 to 200 m). With an average flow at the mouth of about 37,400 cubic feet per second (1,060 m /s),

1904-552: Is likely that Yamhill was the 19th century white settlers' name for a tribe of Native Americans , a Kalapuya people who inhabited the region. The Yamhill people were among 27 bands and tribes moved to the Grand Ronde Indian Reservation , formally established in 1857. Formed by the confluence of the South Yamhill and North Yamhill rivers about 3 miles (4.8 km) east of McMinnville,

2023-635: Is of indigenous origin, deriving from the French pronunciation of the name of a Clackamas Native American village. However, Native American languages in Oregon were very similar, so the name may also be derived from Kalapuya dialects. Around the year 1850, the Kalapuya numbered between 2,000 and 3,000 and were distributed among several groups. These figures are only speculative; there may have been as few as eight subgroups or as many as 16. In that time period,

2142-525: Is privately owned, while 36 percent is publicly owned. The U.S. Forest Service manages 30 percent of the watershed, the U.S. Bureau of Land Management 5 percent, and the State of Oregon 1 percent. Sixty-eight percent of the watershed is forested; agriculture, concentrated in the Willamette Valley, makes up 19 percent, and urban areas cover 5 percent. More than 81,000 miles (130,000 km) of roads criss-cross

2261-500: Is responsible for Corps of Engineers policy and plans the future direction of all other USACE organizations. It comprises the executive office and 17 staff principals. USACE has two civilian directors who head up Military and Civil Works programs in concert with their respective DCG for the mission area. The U.S. Army Corps of Engineers is organized geographically into eight permanent divisions, one provisional division, one provisional district, and one research command reporting directly to

2380-505: Is supervised by the civilian Assistant Secretary of the Army (Civil Works) . Three deputy commanding generals (major generals) report to the chief of engineers, who have the following titles: Deputy Commanding General, Deputy Commanding General for Civil and Emergency Operation, and Deputy Commanding General for Military and International Operations. The Corps of Engineers headquarters is located in Washington, D.C. The headquarters staff

2499-819: The Clackamas River are owned by Portland General Electric . These include the River Mill Hydroelectric Project , the Oak Grove project, and the dam at Timothy Lake . The 50 or so crossings of the Willamette River include many historic structures, such as the Van Buren Street Bridge , a swing bridge . Built in 1913, it carries Oregon Route 34 (Corvallis–Lebanon Highway) over the river upstream of RM 131 (RK 211) in Corvallis. The machinery to operate

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2618-570: The Coast Fork Willamette River , and Dorena on the Row River . Due to these tall dams, Chinook salmon and steelhead are blocked from roughly half of their historic habitat and spawning grounds on the Willamette's major tributaries. Unable to live and reproduce as they once did, they have been "brought to the brink of extinction". Endangered species listings and a subsequent lawsuit by Willamette Riverkeeper led to

2737-612: The Farallon Plate beneath the North American Plate , creating the forearc basin that would later become the Willamette Valley. The valley was initially part of the continental shelf , rather than a separate inland sea. Many layers of marine deposits formed in the forearc basin and cover the older Siletz River Volcanics. About 20 to 16 million years ago, uplift formed the Coast Range and separated

2856-696: The Federal Emergency Management Agency (FEMA) through its security planning, force protection, research and development, disaster preparedness efforts, and quick response to emergencies and disasters. The CoE conducts its emergency response activities under two basic authorities — the Flood Control and Coastal Emergency Act ( Pub. L.   84–99 ), and the Stafford Disaster Relief and Emergency Assistance Act ( Pub. L.   93–288 ). In

2975-642: The Missoula Floods —a series of large outpourings originating at Glacial Lake Missoula in Montana—swept down the Columbia River and backfilled the Willamette watershed. Each flood produced "discharges that exceeded the annual discharge of all the present-day rivers of the world combined". Filling the Willamette basin to depths of 400 feet (120 m) in the Portland region, each flood created

3094-678: The Oregon State Capitol in Salem. Evidence suggests that massive quakes of 8 or more on the Richter scale have occurred historically in the Cascadia subduction zone off the Oregon coast, most recently in 1700 CE , and that others as strong as 9 on the Richter scale occur every 500 to 800 years. The basin's high population density, its nearness to this subduction zone, and its loose soils, which tend to amplify shaking, make

3213-505: The Oregon Trail . The river was an important transportation route in the 19th century, although Willamette Falls , just upstream from Portland, was a major barrier to boat traffic. In the 21st century, major highways follow the river, and roads cross the main stem on approximately 30 different bridges. More than half a dozen bridges not open to motorized vehicles provide separate crossings for bicycles and pedestrians, mostly in

3332-687: The Sandy River did the explorers learn about their oversight. William Clark returned down the Columbia and entered the Willamette River in April 1806. Fur trappers originally working for the Pacific Fur Company (PFC)) and subsequently for the North West Company (NWC) were next to visit the Willamette River and various tributaries. The Siskiyou Trail (or California-Oregon Trail) originally developed by Indigenous people,

3451-857: The Siletz , the Nestucca , the Trask , and the Wilson to the west; the Nehalem and the Clatskanie to the northwest, and the Columbia River to the north. About 2.5 million people lived in the Willamette River basin as of 2010, about 65 percent of the population of Oregon. As of 2009, the basin contained 20 of the 25 most populous cities in Oregon. These cities include Springfield, Eugene, Corvallis, Albany, Salem, Keizer, Newberg, Oregon City, West Linn, Milwaukie, Lake Oswego, and Portland. The largest

3570-415: The U.S. federal government . The main channel, which is the primary navigational conduit for Portland's harbor and riverside industrial areas, is 40 feet (12 m) deep and varies in width from 600 to 1,900 feet (180 to 580 m), although the river broadens to 2,000 feet (610 m) in some of its lower reaches. This channel enters the Columbia about 101 miles (163 km) from the Columbia's mouth on

3689-675: The United States Army held engineer commissions early in their careers. All transferred to other branches before being promoted to the top position. They were Alexander Macomb , George B. McClellan , Henry W. Halleck , Douglas MacArthur , and Maxwell D. Taylor . Occasional civil disasters, including the Great Mississippi Flood of 1927 , resulted in greater responsibilities for the Corps of Engineers. The aftermath of Hurricane Katrina in New Orleans and

Yamhill River - Misplaced Pages Continue

3808-667: The collapse of the Francis Scott Key Bridge in Baltimore provide other examples of this. The Chief of Engineers and Commanding General (Lt. general) of U.S. Army Corps of Engineers has three mission areas: combat engineers, military construction, and civil works. For each mission area the Chief of Engineers/Commanding General is supervised by a different person. For civil works the Commanding General

3927-609: The eastern United States , mainly the Upland South borderlands of Missouri, Iowa, and the Ohio Valley. Many of these emigrants followed the Oregon Trail , a 2,170-mile (3,490 km) trail across western North America that began at Independence, Missouri , and ended at various locations near the mouth of the Willamette River. Although people had been traveling to Oregon since 1836, large-scale migration did not begin until 1843, when nearly 1,000 pioneers headed westward. Over

4046-526: The main stem Willamette meanders generally north for 187 miles (301 km) to the Columbia River . The river's two most significant course deviations occur at Newberg , where it turns sharply east, and about 18 miles (29 km) downstream from Newberg, where it turns north again. Near its mouth north of downtown Portland , the river splits into two channels that flow around Sauvie Island . Used for navigation purposes, these channels are managed by

4165-606: The 1940s through the 1960s and are operated by the United States Army Corps of Engineers (USACE). Of those 13, 9 produce hydropower. Flood-control dams operated by the USACE are estimated to hold up to 27 percent of the Willamette's runoff. They are used to regulate river flows so as to cut peaks off floods and increase low flows in late summer and autumn, and to divert water into deeper, narrower channels to prevent flooding. A relatively small of amount of

4284-453: The 1960s, Oregon Governor Tom McCall led a push for stronger pollution controls on the Willamette. In this, he was encouraged by Robert (Bob) Straub —the state treasurer and future Oregon governor (1975)—who first proposed a Willamette Greenway program during his 1966 gubernatorial campaign against McCall. The Oregon State Legislature established the program in 1967. Through it, state and local governments cooperated in creating or improving

4403-578: The Army Corps of Engineers contributed to the success of numerous missions throughout the Civil War. They were responsible for building pontoon and railroad bridges, forts and batteries, destroying enemy supply lines (including railroads), and constructing roads for the movement of troops and supplies. Both sides recognized the critical work of engineers. On 6 March 1861, once the South had seceded from

4522-458: The Army and the Air Force use to train, house, and deploy troops . USACE built and maintained navigation systems and ports provide the means to deploy vital equipment and other material. Corps of Engineers Research and Development (R&D) facilities help develop new methods and measures for deployment, force protection, terrain analysis, mapping, and other support. USACE directly supports

4641-825: The Cascade Range to 10 feet (3.0 m) at the mouth on the Columbia River. Watersheds bordering the Willamette River basin are those of the Little Deschutes River to the southeast, the Deschutes River to the east, and the Sandy River to the northeast; the North Umpqua and Umpqua rivers to the south; coastal rivers including (from south to north) the Siuslaw , the Alsea , the Yaquina ,

4760-472: The City of Portland and the State of Oregon to dramatically reduce combined sewer overflows (CSOs) led to Portland's Big Pipe Project . The project, part of a related series of Portland CSO projects completed in late 2011 at a cost of $ 1.44 billion, separates the city's sanitary sewer lines from storm-water inputs that sometimes overwhelmed the combined system during heavy rains. When that occurred, some of

4879-603: The Clackamas' tribal population was roughly 1,800. The U.S. Census Bureau estimated that the Chinook population was nearly 5,000, though not all of the Chinook lived on the Willamette. The Chinook territory encompassed the lower Columbia River valley and significant stretches of the Pacific coast on both the north and the south side of the Columbia's mouth. At times, however, the Chinook territory extended even farther south in

Yamhill River - Misplaced Pages Continue

4998-478: The Columbia River. Between the 1850s and the 1960s, channel-straightening and flood control projects, as well as agricultural and urban encroachment, cut the length of the river between the McKenzie River confluence and Harrisburg by 65 percent. Similarly, the river was shortened by 40 percent in the stretch between Harrisburg and Albany. Interstate 5 and three branches of Oregon Route 99 are

5117-554: The Columbia to Bachelor Island . Rockwell's survey was extremely detailed, including 17,782 hydrographic soundings. His work helped open the port of Portland to commerce. In the second half of the 19th century, the USACE dredged channels and built locks and levees in the Willamette's watershed. Although products such as lumber were often transported on an existing network of railroads in Oregon, these advances in navigation helped businesses deliver more goods to Portland, feeding

5236-797: The Corps of Engineers in March 1863. Civil works are managed and supervised by the Assistant Secretary of the Army . Army civil works include three U.S. Congress -authorized business lines: navigation, flood and storm damage protection, and aquatic ecosystem restoration. Civil works is also tasked with administering the Clean Water Act Section 404 program, including recreation, hydropower, and water supply at USACE flood control reservoirs, and environmental infrastructure. The civil works staff oversee construction, operation, and maintenance of dams, canals and flood protection in

5355-603: The Engineer Regiment is commanded by the Engineer Commandant, currently a position filled by an Army brigadier general. The Engineer Regiment includes the U.S. Army Engineer School (USAES) which publishes its mission as: Generate the military engineer capabilities the Army needs: training and certifying Soldiers with the right knowledge, skills, and critical thinking; growing and educating professional leaders; organizing and equipping units; establishing

5474-798: The Eugene area, and several others are exclusively for rail traffic. There are also ferries that convey cars, trucks, motorcycles, bicycles, and pedestrians across the river for a fare and provided river conditions permit. They are the Buena Vista Ferry between Marion County and Polk County south of Independence and Salem, the Wheatland Ferry between Marion County and Polk County north of Salem and Keizer, and Canby Ferry in Clackamas County north of Canby. Since 1900, more than 15 large dams and many smaller ones have been built in

5593-788: The HBC merged with the NWC. In 1825 a new Fort Vancouver headquarters was built on the north shore of the Columbia closer to the Willamette, and Fort George was closed. Alexander Roderick McLeod traveled up the Willamette in 1826 and 1827, to the Umpqua and the Rogue rivers. In 1829 Lucier established a land claim near the Champoeg trading post and started to settle, soon joined by Gervais (1831), Pierre Belleque (1833) and 77 French Canadian settlers by 1836. By 1843, approximately 100 newcomer families lived in

5712-950: The HQ. Within each division, there are several districts. Districts are defined by watershed boundaries for civil works projects and by political boundaries for military projects. U.S. Army engineer units outside of USACE Districts and not listed below fall under the Engineer Regiment of the U.S. Army Corps of Engineers, which comprises the majority of Army engineer soldiers. The Regiment includes combat engineers , whose duties are to breach obstacles; construct fighting positions, fixed/floating bridges, and obstacles and defensive positions; place and detonate explosives; conduct route clearance operations; emplace and detect landmines; and fight as provisional infantry when required. It also includes support engineers, who are more focused on construction and sustainment. Headquartered at Fort Leonard Wood, MO,

5831-519: The Middle and Coast forks and the McKenzie , Long Tom , Marys , Calapooia , Santiam , Luckiamute , Yamhill , Molalla , Tualatin , and Clackamas rivers. Beginning at 438 feet (134 m) above sea level, the main stem descends 428 feet (130 m) between source and mouth, or about 2.3 feet per mile (0.4 m per km). The gradient is slightly steeper from the source to Albany than it

5950-419: The Native Americans. Upper-river tribes caught steelhead and salmon, often by building weirs across tributary streams. Tribes of the northern Willamette Valley practiced a generally settled lifestyle. The Chinooks lived in great wooden lodges , practiced slavery , and had a well-defined caste system. People of the south were more nomadic, traveling from place to place with the seasons. They were known for

6069-491: The Navigation of the Ohio and Mississippi Rivers" and to remove sand bars on the Ohio and "planters, sawyers, or snags" (trees fixed in the riverbed) on the Mississippi, for which the Corps of Engineers was identified as the responsible agency. Separately authorized on 4 July 1838, the Corps of Topographical Engineers consisted only of officers and was used for mapping and the design and construction of federal civil works and other coastal fortifications and navigational routes. It

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6188-510: The PFC. Free trappers Registre Bellaire, John Day and Alexander Carson hunted and traded furs during the winter of 1813-14 along the Willamette. About thirty NWC employees were stationed at the Champoeg post, now called the Willamette Trading Post , along with freemen housed in two huts and Kalapuya nearby. Nez Perce and Cayuse warned the NWC to stay out of the Willamette Valley hunting grounds. Skirmishes went on for several years over fishing and hunting grounds contended by several groups. By

6307-462: The Pacific Ocean. The smaller Multnomah Channel , a distributary , is 21 miles (34 km) long, about 600 feet (180 m) wide, and 40 feet (12 m) deep. It ends about 14.5 miles (23.3 km) farther downstream on the Columbia, near St. Helens in Columbia County . Proposals have been made for deepening the Multnomah Channel to 43 feet (13 m) in conjunction with roughly 103.5 miles (166.6 km) of tandem-maintained navigation on

6426-527: The U.S., as well as a wide range of public works throughout the world. Some of its dams, reservoirs, and flood control projects also serve as public outdoor recreation facilities. Its hydroelectric projects provide 24% of U.S.  hydropower capacity. The Corps of Engineers is headquartered in Washington, D.C. , and has a budget of $ 7.8 billion (FY2021). The corps's mission is to "deliver vital public and military engineering services; partnering in peace and war to strengthen our nation's security, energize

6545-412: The Union, its legislature passed an act to create a Confederate Corps of Engineers. The South was initially at a disadvantage in engineering expertise; of the initial 65 cadets who resigned from West Point to accept positions with the Confederate Army, only seven were placed in the Corps of Engineers. The Confederate Congress passed legislation that authorized a company of engineers for every division in

6664-413: The Willamette Falls Locks have been inactive. As commerce and industry flourished on the lower river, most of the original settlers acquired farms in the upper Willamette Valley. By the late 1850s, farmers had begun to grow crops on most of the available fertile land. The settlers increasingly encroached on Native American lands. Skirmishes between natives and settlers in the Umpqua and Rogue valleys to

6783-437: The Willamette River was divided into two stretches: the 27-mile (43 km) lower stretch from Portland to Oregon City—which allowed connection with the rest of the Columbia River system—and the upper reach, which encompassed most of the Willamette's length. Any boats whose owners found it absolutely necessary to get past the falls had to be portaged . This led to competition for business among steam portage companies. In 1873,

6902-472: The Willamette Valley especially vulnerable to damage from strong earthquakes. The Willamette River drains a region of 11,478 square miles (29,730 km ), which is 12 percent of the total area of Oregon. Bounded by the Coast Range to the west and the Cascade Range to the east, the river basin is about 180 miles (290 km) long and 100 miles (160 km) wide. Elevations within the watershed range from 10,495 feet (3,199 m) at Mount Jefferson in

7021-434: The Willamette Valley were further divided into groups including the Kalapuyan-speaking Yamhill and Atfalati (Tualatin) (both Northern Kalapuya), Central Kalapuya like the Santiam , Muddy Creek (Chemapho), Long Tom (Chelamela), Calapooia (Tsankupi), Marys River (Chepenafa) and Luckiamute, and the Yoncalla or Southern Kalapuya, as well other tribes such as the Chuchsney-Tufti, Siuslaw and Molala . The name Willamette

7140-435: The Willamette Valley. The total native population was estimated at 15,000. The indigenous peoples of the Willamette River practiced a variety of life ways. Those on the lower river, slightly closer to the coast, often relied on fishing as their primary economic mainstay. Salmon was the most important fish to Willamette River tribes as well as to the Native Americans of the Columbia River, where white traders traded fish with

7259-417: The Willamette Valley. These included the Kalapuya , the Chinook , and the Clackamas . The territory of the Clackamas encompassed the northeastern portion of the basin, including the Clackamas River (with which their name is shared). Although it is unclear exactly when, the territory of the Chinook once extended across the northern part of the watershed, through the Columbia River valley. Indigenous peoples of

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7378-423: The Willamette basin. The highest flow recorded at this station was 420,000 cubic feet per second (11,893 m /s) on February 9, 1996, during the Willamette Valley Flood of 1996 , and the minimum was 4,200 cubic feet per second (120 m /s) on July 10, 1978. The highest recorded flow of 635,000 cubic feet per second (18,000 m /s) for the Willamette at a different gauge in Portland occurred during

7497-428: The Willamette ranks 19th in volume among rivers in the United States and contributes 12 to 15 percent of the total flow of the Columbia River. The Willamette's flow varies considerably season to season, averaging about 8,200 cubic feet per second (230 m /s) in August to more than 79,000 cubic feet per second (2,200 m /s) in December. The U.S. Geological Survey (USGS) operates five stream gauges along

7616-404: The Willamette's drainage basin, 13 of which are operated by the U.S. Army Corps of Engineers (USACE). The dams are used primarily to produce hydroelectricity , to maintain reservoirs for recreation, and to prevent flooding. The river and its tributaries support 60 fish species, including many species of salmon and trout ; this is despite the dams, other alterations, and pollution (especially on

7735-399: The Willamette, continued on until the falls portage (present-day Oregon City ) and finished their journey at a flattening of both banks, the later site of Champoeg . A first trading post was established. By early 1813, William Wallace and John C. Halsey established a second outpost, Wallace House , farther south, north of present-day Salem. By the end of the War of 1812 , the NWC acquired

7854-418: The basalt with up to 1,000 feet (300 m) of silt in the Portland and Tualatin basins. During the Pleistocene , beginning roughly 2.5 million years ago, volcanic activity in the Cascades combined with a cool, moist climate to produce further heavy sedimentation across the basin, and braided rivers created alluvial fans spreading down from the east. Between about 15,500 and 13,000 years ago,

7973-416: The basin from the Pacific Ocean. Basalts of the Columbia River Basalt Group , from eruptions primarily in eastern Oregon , flowed across large parts of the northern half of the basin about 15 million years ago. They covered the Tualatin Mountains (West Hills), most of the Tualatin Valley , and the slopes of hills farther south, with up to 1,000 feet (300 m) of lava . Later deposits covered

8092-421: The city's first officially recognized public swimming beach, Poet's Beach . There are more than 20 major dams on the Willamette's tributaries, as well as a complex series of levees and channels to control the river's flow. The only dam on the Willamette's main stem is the Willamette Falls Dam, a low weir -type structure at Willamette Falls that diverts water into the headraces of the adjacent mills and

8211-414: The city's growing economy. Trade goods from the Columbia basin north of Portland could also be transported southward on the Willamette due to the deeper channels made at the Willamette's mouth. By the early 20th century, major river-control projects had begun to take place. Levees were constructed along the river in most urban areas, and Portland built concrete walls to protect its downtown sector. In

8330-441: The city, which lies to its right at RM 5 (RK 8). Here Palmer Creek enters from the right. Below Dayton, the river enters the Willamette at its RM 55 (RK 89) south of Newberg. In 1900 a Yamhill River lock and dam lock and dam was completed about 1.5 miles downriver from Lafayette, Oregon . The lock was decommissioned in 1954. The dam was deliberately destroyed in 1963 to allow better passage for salmon on

8449-423: The construction of the Willamette Falls Locks bypassed the falls and allowed easy navigation between the upper and lower river. Each lock chamber measured 210 feet (64 m) long and 40 feet (12 m) wide, and the canal was originally operated manually before it switched to electrical power. Usage of the locks peaked in the 1940s, and by the early 21st century, the lock system was little used. Since 2011,

8568-542: The controlled burning of woodlands to create meadows for hunting and plant gathering (especially camas ). The Willamette River first appeared in written records in 1792, when it was observed by British Lieutenant William Robert Broughton of the Vancouver Expedition , led by George Vancouver . The 1805-1806 Lewis and Clark Expedition originally missed the mouth of the Willamette. On their return journey, only after receiving directions from natives along

8687-601: The creation of a "Chief Engineer for the Army". Congress authorized a corps of engineers for the United States on 11 March 1779. The Corps as it is known today came into being on 16 March 1802, when the president was authorized to "organize and establish a Corps of Engineers ... that the said Corps ... shall be stationed at West Point in the State of New York and shall constitute a Military Academy ." A Corps of Topographical Engineers , authorized on 4 July 1838, merged with

8806-597: The economy and reduce risks from disasters." Its most visible civil works missions include: The history of United States Army Corps of Engineers can be traced back to the American Revolution . On 16 June 1775, the Continental Congress organized the Corps of Engineers, whose initial staff included a chief engineer and two assistants. Colonel Richard Gridley became General George Washington 's first chief engineer. One of his first tasks

8925-656: The field; by 1865, the CSA had more engineer officers serving in the field of action than the Union Army. One of the main projects for the Army Corps of Engineers was constructing railroads and bridges. Union forces took advantage of such Confederate infrastructure because railroads and bridges provided access to resources and industry. The Confederate engineers, using slave labor, built fortifications that were used both offensively and defensively, along with trenches that made them harder to penetrate. This method of building trenches

9044-447: The following decades, many large dams were built on Cascade Range tributaries of the Willamette. The Army Corps of Engineers operates 13 such dams, which affect flows from about 40 percent of the basin. Most of them do not have fish ladders. With development in and near the river came increased pollution. By the late 1930s, efforts to stem the pollution led to formation of a state sanitary board to oversee modest cleanup efforts. In

9163-1120: The following: The U.S. Army Corps of Engineers environmental mission has two major focus areas: restoration and stewardship . The Corps supports and manages numerous environmental programs, that run the gamut from cleaning up areas on former military installations contaminated by hazardous waste or munitions to helping establish/reestablish wetlands that helps endangered species survive. Some of these programs include Ecosystem Restoration, Formerly Used Defense Sites, Environmental Stewardship, EPA Superfund , Abandoned Mine Lands, Formerly Utilized Sites Remedial Action Program , Base Realignment and Closure, 2005 , and Regulatory. This mission includes education as well as regulation and cleanup. The U.S. Army Corps of Engineers has an active environmental program under both its Military and Civil Programs. The Civil Works environmental mission that ensures all USACE projects, facilities and associated lands meet environmental standards. The program has four functions: compliance, restoration, prevention, and conservation. The Corps also regulates all work in wetlands and waters of

9282-475: The founding of the town in 1829. McLoughlin attempted to persuade the HBC (which still held sway over the area) to allow American settlers to live on the land, and provided significant help to American colonization of the area, all against the HBC's orders. Oregon City prospered because of the lumber and grist mills that were run by the water power of Willamette Falls, but the falls formed an impassable barrier to river navigation. Linn City (originally Robins Nest)

9401-586: The goods consumed by Americans and more than half of the nation's oil imports are processed through deepwater ports maintained by the Corps of Engineers, which maintains more than 12,000 miles (19,000 km) of commercially navigable channels across the U.S. In both its Civil Works mission and Military Construction program, the Corps of Engineers is responsible for billions of dollars of the nation's infrastructure. For example, USACE maintains direct control of 609 dams, maintains or operates 257 navigation locks, and operates 75 hydroelectric facilities generating 24% of

9520-625: The government to a part of the Coast Reservation that later became the Grande Ronde Reservation . Between 1879 and 1885, the Willamette River was charted by Cleveland S. Rockwell , a topographical engineer and cartographer for the United States Coast and Geodetic Survey . Rockwell surveyed the lower Willamette from the foot of Ross Island through Portland to the Columbia River and then downstream on

9639-583: The invasion of Normandy. During World War II, the Army Corps of Engineers in the European Theater of Operations was responsible for building numerous bridges, including the first and longest floating tactical bridge across the Rhine at Remagen , and building or maintaining roads vital to the Allied advance across Europe into the heart of Germany. In the Pacific theater, the "Pioneer troops" were formed,

9758-657: The largest of these originally weighed about 160 short tons (150 t). The northern part of the watershed is underlain by a network of faults capable of producing earthquakes at any time, and many small quakes have been recorded in the basin since the mid-19th century. In 1993, the Scotts Mills earthquake —the largest recent earthquake in the valley, measuring 5.6 on the Richter scale —was centered near Scotts Mills , about 34 miles (55 km) south of Portland. It caused $ 30 million in damage, including harm to

9877-835: The largest water storage capacity, at 477,700 acre-feet (589,200,000 m ). The other 11 dams are Big Cliff on the North Santiam River; Green Peter and Foster on the Santiam River ; Cougar on the South Fork McKenzie River ; Blue River on the Blue River ; Fern Ridge on the Long Tom River ; Hills Creek and Dexter on the Middle Fork Willamette River; Fall Creek on Fall Creek ; Cottage Grove on

9996-541: The lower river and in the area around its mouth on the Columbia. Indigenous peoples lived throughout the upper reaches of the basin as well. Rich with sediments deposited by flooding and fed by prolific rainfall on the western side of the Cascades, the Willamette Valley is one of the most fertile agricultural regions in North America, and it was thus the destination of many 19th-century pioneers traveling west along

10115-476: The main stem Yamhill River flows generally east for about 11 miles (18 km) to the Willamette River, a tributary of the Columbia River . At about RM 9 (RK 14), Hawn Creek and then Millican Creek enter from the left as the Yamhill nears Lafayette , which lies to the river's left. Beyond Lafayette, Henry Creek enters from the left. Near Dayton, the river passes under Oregon Route 18 before skirting

10234-646: The mid-19th century, Corps of Engineers' officers ran Lighthouse Districts in tandem with U.S. Naval officers. The Army Corps of Engineers played a significant role in the American Civil War . Many of the men who would serve in the top leadership in this organization were West Point graduates. Several rose to military fame and power during the Civil War. Some examples include Union generals George McClellan , Henry Halleck , and George Meade ; and Confederate generals Robert E. Lee , Joseph Johnston , and P.G.T. Beauregard . The versatility of officers in

10353-568: The military construction mission on 1 December 1941, after the Quartermaster Department struggled with the expanding mission, the Corps built facilities at home and abroad to support the U.S. Army and Air Force. During World War II the USACE program expanded to more than 27,000 military and industrial projects in a $ 15.3 billion mobilization effort. Included were aircraft, tank assembly, and ammunition plants; camps for 5.3 million soldiers; depots, ports, and hospitals; and

10472-651: The military construction mission, the chief of engineers is directed and supervised by the Assistant Secretary of the Army for installations, environment, and energy, whom the President appoints and the Senate confirms. Military construction relates to construction on military bases and worldwide installations. On 16 June 1775, the Continental Congress , gathered in Philadelphia , granted authority for

10591-480: The military in the battle zone, making expertise available to commanders to help solve or avoid engineering (and other) problems. Forward Engineer Support Teams, FEST-A's or FEST-M's, may accompany combat engineers to provide immediate support, or to reach electronically into the rest of USACE for the necessary expertise. A FEST-A team is an eight-person detachment; a FEST-M is approximately 36. These teams are designed to provide immediate technical-engineering support to

10710-440: The nation's hydropower and three percent of its total electricity. USACE inspects over 2,000 Federal and non-Federal levees every two years. Four billion gallons of water per day are drawn from the Corps of Engineers' 136 multi-use flood control projects comprising 9,800,000 acre-feet (12.1 km ) of water storage, making it one of the United States' largest water supply agencies. The 249th Engineer Battalion (Prime Power) ,

10829-664: The next 25 years, some 500,000 settlers traveled the Oregon Trail, to reach the Willamette Valley. Starting in the 1830s, Oregon City developed near Willamette Falls. It was incorporated in 1844, becoming the first city west of the Rocky Mountains to have that distinction. John McLoughlin , the Hudson's Bay Company (HBC) superintendent of the Columbia District , was one of the major contributors to

10948-637: The non-profit Willamette Riverkeeper organization designated the full length of the river as the Willamette River Water Trail. Four years later, the National Park Service added the Willamette water trail—expanded to 217 miles (349 km) to include some of the major tributaries—to its list of National Water Trails . The water trail system is meant to protect and restore waterways in the United States and enhance recreation on and near them. A 1991 agreement between

11067-415: The only active duty unit in USACE, generates and distributes prime electrical power in support of warfighting, disaster relief, stability and support operations as well as provides advice and technical assistance in all aspects of electrical power and distribution systems. The battalion deployed in support of recovery operations after 9/11 and was instrumental in getting Wall Street back up and running within

11186-650: The rapid construction of such landmark projects such as the Manhattan Project at Los Alamos, Hanford and Oak Ridge among other places, and the Pentagon , the Department of Defense headquarters across the Potomac from Washington, DC. In civilian projects, the Corps of Engineers became the lead federal navigation and flood control agency. Congress significantly expanded its civil works activities, becoming

11305-479: The raw sewage in the system flowed into the river instead of into the city's wastewater treatment plant. The Big Pipe project and related work reduces CSO volume on the lower river by about 94 percent. In June 2014, Dean Hall became the first person to swim the entire length of the Willamette River. He swam 184 miles (296 km) from Eugene to the river mouth in 25 days. In 2017, Human Access Project partnered with Portland Parks & Recreation to open

11424-540: The river at the Morrison Bridge . The Willamette River basin was created primarily by plate tectonics and volcanism and was altered by erosion and sedimentation, including deposits from enormous glacial floods as recent as 13,000 years ago. The oldest rocks beneath the Willamette Valley are the Siletz River Volcanics . About 35 million years ago, these rocks were subducted by

11543-482: The river in Portland. The 3,700-foot (1,100 m) bridge is the only cantilevered deck truss in Oregon. United States Army Corps of Engineers The United States Army Corps of Engineers ( USACE ) is the military engineering branch of the United States Army . A direct reporting unit (DRU), it has three primary mission areas: Engineer Regiment , military construction , and civil works . USACE has 37,000 civilian and military personnel, making it one of

11662-579: The river's lower reaches). Part of the Willamette Floodplain was established as a National Natural Landmark in 1987, and the river was named as one of 14 American Heritage Rivers in 1998. The upper tributaries of the Willamette originate in the mountains south and southeast of Eugene, Oregon . Formed by the confluence of the Middle Fork Willamette River and the Coast Fork Willamette River near Springfield ,

11781-470: The river, at Harrisburg, Corvallis, Albany, Salem, and Portland. The average discharge at the lowermost gauge, near the Morrison Bridge in Portland, was 33,220 cubic feet per second (941 m /s) between 1972 and 2013. Located at river mile (RM) 12.8 or river kilometer (RK) 20.6, the gauge measures the flow from an area of 11,200 square miles (29,000 km ), roughly 97 percent of

11900-446: The river. The site of the lock and dam is now a county park. Willamette River Originally created by plate tectonics about 35 million years ago and subsequently altered by volcanism and erosion, the river's drainage basin was significantly modified by the Missoula Floods at the end of the most recent ice age . Humans began living in the watershed over 10,000 years ago. There were once many tribal villages along

12019-443: The south, settled from this muddy water to form today's valley floor. The floods carried Montana icebergs well into the basin, where they melted and dropped glacial erratics onto the land surface. These rocks, composed of granite and other materials common to central Montana but not to the Willamette Valley, include more than 40 boulders, each at least 3 feet (0.9 m) in diameter. Before being partly chipped away and removed,

12138-583: The southwest of the Willamette River led the Oregon state government to remove the natives by military force. They were first led off their traditional lands to the Willamette Valley, but soon were marched to the Coast Indian Reservation . In 1855, Joel Palmer , an Oregon legislator, negotiated a treaty with the Willamette Valley tribes, who, although unhappy with the treaty, ceded their lands to non-natives. The natives were then relocated by

12257-424: The swing span was removed in the 1950s. The Oregon City Bridge , built in 1922, replaced a suspension span constructed at the site in 1888. It carries Oregon Route 43 over the river at about RM 26 (RK 42) between Oregon City and West Linn . The Ross Island Bridge carries U.S. Route 26 ( Mount Hood Highway ) over the river at RM 14 (RK 23). It is one of 10 highway bridges crossing

12376-851: The three mission areas are administered by a lieutenant general known as the chief of engineers /commanding general. The chief of engineers commands the Engineer Regiment, comprising combat engineer , rescue, construction, dive, and other specialty units, and answers directly to the Chief of Staff of the Army . Combat engineers, sometimes called sappers , form an integral part of the Army's combined arms team and are found in all Army service components: Regular Army, National Guard , and Army Reserve . Their duties are to breach obstacles; construct fighting positions, fixed/floating bridges, and obstacles and defensive positions; place and detonate explosives; conduct route clearance operations; emplace and detect landmines; and fight as provisional infantry when required. For

12495-1065: The two major highways that follow the river for its entire length. Communities along the main stem include Springfield and Eugene in Lane County ; Harrisburg in Linn County ; Corvallis in Benton County ; Albany in Linn and Benton counties; Independence in Polk County ; Salem in Marion County ; Newberg in Yamhill County ; Oregon City , West Linn , Milwaukie , and Lake Oswego in Clackamas County ; and Portland in Multnomah and Washington counties. Significant tributaries from source to mouth include

12614-605: The vicinity of the Willamette on a section referred to as French Prairie . By 1841, members of the United States Exploring Expedition came through the Siskiyou Trail. They noted extensive salmon fishing by natives at Willamette Falls, much like that at Celilo Falls on the Columbia River. In the middle part of the 19th century the Willamette Valley's fertile soils, pleasant climate, and abundant water attracted thousands of settlers from

12733-574: The warfighter or in a disaster area. Corps of Engineers' professionals use the knowledge and skills honed on both military and civil projects to support the U.S. and local communities in the areas of real estate, contracting, mapping, construction, logistics, engineering, and management experience. Prior to their respective troop withdrawals in 2021, this included support for rebuilding Iraq , establishing infrastructure in Afghanistan , and supporting international and inter-agency services. In addition,

12852-483: The water stored in the reservoirs is used for irrigation . Cougar Dam on the South Fork McKenzie River and Detroit Dam on the North Santiam River are the two tallest dams in the Willamette River basin. Detroit Dam is 463 feet (141 m) high and stores 455,000 acre-feet (561,000,000 m ) of water. Lookout Point Dam on the Middle Fork Willamette River , forming Lookout Point Lake , has

12971-678: The watershed. In 1987, the U.S. Secretary of the Interior designated 713 acres (289 ha) of the watershed in Benton County as a National Natural Landmark . This area is the Willamette Floodplain , the largest remaining unplowed native grassland in the North Pacific geologic province, which encompasses most of the Pacific Northwest coast. For at least 10,000 years, a variety of indigenous peoples populated

13090-439: The winter of 1818-19, Thomas McKay led a hunting brigade farther south towards the sources of the Willamette River and reached the upper Umpqua River . More violent skirmishes were fought. Most brigade members returned to Fort George (formerly called Fort Astoria ). Louis LaBonté, Joseph Gervais , Étienne Lucier , Louis Kanota, and Louis Pichette (dit DuPré) remained in the Willamette Valley as free trappers. Meanwhile, in 1821

13209-474: The work of almost 26,000 civilians on civil-works programs throughout USACE provides a training ground for similar capabilities worldwide. USACE civilians volunteer for assignments worldwide. For example, hydropower experts have helped repair, renovate, and run hydropower dams in Iraq in an effort to help get Iraqis to become self-sustaining. USACE supports the United States' Department of Homeland Security and

13328-503: The world's largest public engineering, design, and construction management agencies. The USACE workforce is approximately 97% civilian, 3% active duty military. The civilian workforce is primarily located in the United States, Europe and in select Middle East office locations. Civilians do not function as active duty military and are not required to be in active war and combat zones; however, volunteer (with pay) opportunities do exist for civilians to do so. The day-to-day activities of

13447-645: Was appointed colonel and commander of all engineers in the Continental Army and, on 17 November 1777, he was promoted to brigadier general. When the Continental Congress created a separate Corps of Engineers in May 1779, Duportail was appointed as its commander. In late 1781 he directed the construction of the allied U.S.-French siege works at the Battle of Yorktown . On 26 February 1783, the Corps

13566-597: Was disbanded. It was re-established during the Presidency of George Washington . From 1794 to 1802, the engineers were combined with the artillery as the Corps of Artillerists and Engineers . The Corps of Engineers, as it is known today, was established on 16 March 1802, when President Thomas Jefferson signed the Military Peace Establishment Act , whose aim was to "organize and establish

13685-402: Was established across the Willamette from Oregon City. After Portland was incorporated in 1851, quickly growing into Oregon's largest city, Oregon City gradually lost its importance as the economic and political center of the Willamette Valley. Beginning in the 1850s, steamboats began to ply the Willamette, despite the fact that they could not pass Willamette Falls. As a result, navigation on

13804-589: Was known as the zigzag pattern. The National Defense Act of 1916 authorized a reserve corps in the Army, and the Engineer Officers' Reserve Corps and the Engineer Enlisted Reserve Corps became one of the branches. Some of these personnel were called into active service for World War I . From the beginning, many politicians wanted the Corps of Engineers to contribute to both military construction and civil works. Assigned

13923-775: Was merged with the Corps of Engineers on 31 March 1863, at which point the Corps of Engineers also assumed the Lakes Survey District mission for the Great Lakes . In 1841, Congress created the Lake Survey . The survey, based in Detroit, Michigan, was charged with conducting a hydrographical survey of the Northern and Northwestern lakes and preparing and publishing nautical charts and other navigation aids. The Lake Survey published its first charts in 1852. In

14042-653: Was to build fortifications near Boston at Bunker Hill . The Continental Congress recognized the need for engineers trained in military fortifications and asked the government of King Louis XVI of France for assistance. Many of the early engineers in the Continental Army were former French officers. Louis Lebègue Duportail , a lieutenant colonel in the French Royal Corps of Engineers, was secretly sent to North America in March 1777 to serve in George Washington 's Continental Army . In July 1777 he

14161-545: Was used to reach farther south. This trail, over 600 miles (970 km) long, stretched from the mouth of the Willamette River near present-day Portland south through the Willamette Valley, crossing the Siskiyou Mountains , and south through the Sacramento Valley to San Francisco . In 1812, William Henry and Alfred Seton paddled up from Fort Astoria (PFC) on the Columbia River into the mouth of

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