The Sts'ailes are an indigenous people from the Lower Mainland region of British Columbia, Canada.
Their band government is the Chehalis First Nation, formerly known as the Chehalis Indian Band,. The band's name community is located on Indian Reserve lands at Chehalis, which is on the lower Harrison River between the towns of Mission and Agassiz. Their band's mailing address is in nearby Agassiz.
The name Sts'ailes means "beating heart," which became the name of their village, located on the west side of the Harrison River. Their usual English name, Chehalis, is identical to that of the much more numerous Chehalis people of southern Puget Sound in Washington. By Sts'ailes tradition, the southern Chehalis were separated from their homeland as a consequence of the Great Flood.
In Sts'ailes tradition, Xals, the Transformer, defeated a powerful shaman known as "the Doctor". Xals turned the shaman to stone, and broke the stone to pieces, spreading the fragments to prevent his return. The heart of the shaman fell on the shores of the home lake (Harrison Lake), and became the place where the Sts'ailes originated. There is evidence of this culture in the form of lithic (stone working) and mortuarial practices going back at least 1500 years.
There is evidence that the Sts'ailes people relied primarily on the salmon from the Fraser-Harrison watershed as their most important food source. Many of their religious ceremonies are derived from significant periods of the year important to the fishery.
While there is no modern link detween the Chehalis tribe of Eastern Washington, and the people (often referred to as Chehalis), their heritage does speak of a flood that separated a southern portion of it's people many years before.