The Wascos: The Wascos were positioned in a key spot along the Columbian River which allowed them to be important traders among the tribes. Their land was one of the most important locations for local aboriginal trade. Their numbers declined between 1822 and 1853 from 900 members to 300 members.
The Wat-la-las: "The Cascade Indians" consisted of several other villages that were largely wiped out by disease, who joined together to form one village. Like the Wascos, their population was also decimated.
The Clackamas: The Clackamas lived south of the Columbia River. Much of their trade and industry came through marriage ties, which contributed to their size. Again, like the other tribes, their population declined steeply due to disease and interference by white settlers.
(Aguilar, 2005a)