Given the below context:  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. The name Willamette 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, 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 about 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...  Guess a valid title for it!
The answer to this question is:
Willamette River