Tseax Cone

Tseax Cone is a volcanic cone in northwestern British Columbia, Canada, notable for producing large lava flows in the late 18th century. The cone and its flows are part of the local volcanic landscape associated with the Northern Cordilleran Volcanic Province.

The area contains extensive, well-preserved lava beds and created a distinctive basaltic terrain that contrasts with surrounding forests. Interpretive trails and a Nisga’a memorial explain the eruption’s impact on local Indigenous communities.

Oral history and geological evidence indicate a late 18th century eruption from Tseax Cone that produced lava flows and toxic gases which caused significant loss of life among nearby Nisga’a settlements. The site is remembered culturally and legally through Nisga’a stewardship and the establishment of a protected area.

Tseax Cone and the associated lava beds lie in the Nass River valley region of northwestern British Columbia, within Nisga’a territory and close to other features of the provincial park.

• Historic eruption: The eruption occurred in the late 18th century and produced lava flows that devastated nearby communities, an event remembered in Nisga'a oral history and marked by a memorial in the park.
• Landscape and access: The site preserves extensive lava-formed terrain that can be viewed from trails and overlooks; visitors should follow local guidance and respect Nisga'a cultural sites.

What to See #

• Nisga'a Memorial Lava Beds Provincial Park: A protected area preserving the lava beds and surrounding forest where the Tseax eruption's flows solidified; contains interpretive signage and a Nisga'a memorial to the eruption's victims.