The Cowichan Tribes speak a "Hul'qumi'num (Island dialect)" of Halkomelem (part of the Coast Salish languages); because the Ts'uubaa-asatx have adopted the dialect of their dominant Salish neighbors, they are classed as part of the Hul'qumi'num linguistic group.
Early settlers to the Lake Cowichan area described "a small tribe of Indians" living in "houses constructed of bark."
During the 19th Century the Lake Cowichan First Nation was decimated by disease and conflict with neighboring groups.
In 1860, a prospector by the name of Samuel Harris travelled to the area seeking minerals and reported that many of the Natives were dead and dying from smallpox.
Archaeological investigations have revealed the historic presence of a village on the north east side of the lake, within the boundaries of the present day Cowichan Lake Indian Reserve.