Yoncalla is a Kalapuyan language once spoken in southwest Oregon

Oregon

Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. In the 19th century it was spoken by the Yoncalla band of the Kalapuya people in the Umpqua River

Umpqua River

The Umpqua River on the Pacific coast of Oregon in the United States is approximately long. One of the principal rivers of the Oregon Coast and known for bass and shad, the river drains an expansive network of valleys in the mountains west of the Cascade Range and south of the Willamette Valley,...

 valley. It is closely related to Central Kalapuya

Central Kalapuya language

Central Kalapuyan was a Kalapuyan language indigenous to the central and southern Willamette Valley in Oregon in the United States. It was spoken by various bands of the Kalapuya peoples who inhabited the valley up through the middle of the 19th century. The language is closely related to Northern...

 and Northern Kalapuya

Northern Kalapuya language

Northern Kalapuyan is a Kalapuyan language indigenous to northwestern Oregon in the United States. It was spoken by Kalapuya groups in the northern Willamette Valley southwest of present-day Portland....

, spoken in the Willamette Valley

Willamette Valley

The Willamette Valley is the most populated region in the state of Oregon of the United States. Located in the state's northwest, the region is surrounded by tall mountain ranges to the east, west and south and the valley's floor is broad, flat and fertile because of Ice Age conditions...

to the north.

The last-known user of the language was Laura Blackery Albertson, who attested to being a partial speaker in 1937.