Tualatin Basin Tribes
Oregon today is home to nine federally recognized tribal nations, plus several unrecognized tribes. These modern tribal governments each include members descending from multiple tribes and bands. The Atfalati were the northernmost band of the Kalapuya who lived along the Tualatin River in present day Washington County. The Atfalati-Kalapuya people were also called Tualatins. Their territory included most of modern Washington County and some of northern Yamhill County.
Confederated Tribes of Grand Ronde’s Land Acknowledgement Statement for Washington County
Washington County was originally inhabited by the Tualatin Band of Kalapuya (also known as the Atfalati, Twalaty, Twalatin, Quality, Tualaty, or Twalati).
It is fair to say the Tualatin Band of Kalapuya inhabited the entirety of Washington County at one time or another, but their most valued homeland was at Wapato Lake, near modern day Gaston. Wapato Lake supplied large amounts of wapato (an aquatic plant with a nutritious tuber much like a potato) to the Tualatin people, who grew camas and oak acorns as well. The Tualatin Band of Kalapuya traded extensively with their neighbors, and also traded with Euro-American settlers. In 1851 the Tualatin Band of Kalapuya signed a treaty which would have retained for them a reservation surrounding Wapato Lake, but it was never ratified by Congress. Instead the Willamette Valley Treaty of January 22, 1855 (which the Tualatin Band of Kalapuya also signed) was ratified by Congress, which provided other rights and benefits for them but not their own reservation. Chief Ki-a-cuts was the treaty signer for the Tualatin Band of Kalapuya, and he was later elected Head Chief at the Grand Ronde Indian Reservation.
As with most of the tribes and bands of western Oregon, disease epidemics brought by Euro-Americans devastated the populations of these peoples, and in some cases their surviving members and/or descendants had either incorporated into neighboring bands or assimilated into the larger settler population out of necessity by the 1850s. After the signing of the Willamette Valley Treaty in 1855 (through which the entire Willamette Basin was ceded to the U.S. in exchange for certain rights and benefits), many of them were moved onto small temporary reservations, and later to the Grand Ronde Indian Reservation where they became members of the Confederated Tribes of Grand Ronde. Their descendants live on as Tribal members today, carrying on the traditions and cultures of their ancestors, the original people of this land.
You can learn more about Tribes local to the Tualatin Basin at the websites below.