At one time the Tsimshian lived on the upper reaches of the Skeena River near present-day Hazelton BC. After a series of disasters befell the people, a prince led a migration away from the cursed land to the coast, where they founded Kitkatla, reputed to be one of the oldest continually inhabited communities on Earth.
Following suit, other Tsimshian chiefs later migrated down the river and began to occupy all the lands of the lower Skeena valley. Over time these groups developed a new dialect of their ancestral language and came to regard themselves as a distinct population, the Tsimshian proper, while still sharing all the rights and customs of the Gitksan, their kin on the upper Skeena.
In 1862 a smallpox epidemic annihilated many Tsimshian people. Further epidemics ravaged their communities until the late 1890s. Altogether, one in four Tsimshian died in a series of at least three large-scale outbreaks, . Lax Kw’alaams began burying their dead without ceremony on Rose Island.
From this time forward many Tsimshian adopted the language, religion, and culture of nearby White colonists, who were predominantly Protestant and English. The Head Chiefs themselves were the ones who led the process of assimilation. Only in the 1970s did Tsimshian communities begin to return to their traditional culture, which appeared first in the school district.
In the 1880s the Anglican missionary William Duncan, with a group of Tsimshian, requested settlement on Annette Island from the U.S. government. After approval, the group founded New Metlakatla in Alaska. Duncan later requested that the community gain reservation status, and eventually, with the passage of the Alaska Native Claims Settlement Act, it became the only Native reservation in the state.
The New Metlakatla Tsimshian maintained their reservation status and holdings exclusive of the Alaska Native Claims Settlement Act. They do not have an associated Native Corporation, although Tsimshian in Alaska may be shareholders of the Sealaska Corporation.
The Annette Island reservation was the only location in Alaska allowed to maintain fish traps, which were otherwise banned when Alaska became a state in 1959. The traps are used to provide food for people living on the reservation. Legally the community was required to use the traps at least once every three years or lose the right permanently. This practice was stopped early in the 2000s and they are no longer allowed.
In British Columbia, the governments of Canada engaged in the British Columbia Treaty Process with First Nation bands in the province. The Tsimshian First Nations pursued negotiations until late 2005 when the Tsimshian Tribal Council, the organization representing each of the First Nations in treaty negotiations, dissolved amid legal and political turmoil.