First inhabitants For at least 10,000 years, a variety of indigenous peoples populated 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 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. However, Native American languages in Oregon were very similar, so the name may also be derived from Kalapuya dialects. in
Eugene engraved with the Kalapuyan word "Whilamut" "Where the river ripples and runs fast" 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, 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 the Willamette Valley. The total native population was estimated at 15,000. practiced
slavery, and had a well-defined
caste system.
18th century 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.
19th century 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 the
Sandy River did the explorers learn about their oversight.
William Clark returned down the Columbia and entered the Willamette River in April 1806. The
Siskiyou Trail (or California-Oregon Trail) originally developed by Indigenous people, was used to reach farther south. This trail, over 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 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 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 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 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 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 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 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 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 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) 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 the Willamette River was divided into two stretches: the 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, the construction of the
Willamette Falls Locks bypassed the falls and allowed easy navigation between the upper and lower river. Each lock chamber measured long and wide, and the canal was originally operated manually before it switched to electrical power. Since 2011, 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 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 the government to a part of the Coast Reservation that later became the
Grande Ronde Reservation. 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 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.
20th and 21st centuries 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. 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. The Oregon State Legislature established the program in 1967. Through it, state and local governments cooperated in creating or improving a system of parks, trails, and wildlife refuges along the river. By 2007 the Greenway had grown to include more than 170 separate land parcels, including 10 state parks. Four years later, the
National Park Service added the Willamette water trail—expanded to 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 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 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 from Eugene to the river mouth in 25 days. ==Dams==