Ash Mountain is the highest summit in the Tuya Range

Tuya Range

The Tuya Range is a range of tuyas, located in the Stikine Ranges of the Cassiar Mountains in the far northr of the Canadian province of British Columbia, near its border with the Yukon Territory and to the southwest of Watson Lake, Yukon, which is the nearest major settlement.-Boundaries and...

 of the Stikine Ranges

Stikine Ranges

The Stikine Ranges are a mountain range in northwestern British Columbia, Canada. They are the northernmost subdivision of the Cassiar Mountains and among the least explored and most undeveloped parts of the province.-Sub-ranges:*Beady Range...

 in northcentral British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, located immediately north of High Tuya Lake at the north end of Tuya Mountains Provincial Park

Tuya Mountains Provincial Park

Tuya Mountains Provincial Park is a provincial park in British Columbia, Canada, protecting the Tuya Range, a volcanic region at the head of the Tuya River. The park is located on the north side of Tuya Lake. The park is named for nearby Tuyas, steep-sided, flat-topped types of volcano....

. It is one of the six tuyas clustered close to Tuya Lake

Tuya Lake

Tuya Lake, located in northwestern British Columbia, Canada, presumably derives its name from the presence of nearby steep-sided, flat-topped volcanoes, known as tuyas...

. The base of the volcano comprises pillow lava

Pillow lava

Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava under water, or subaqueous extrusion. Pillow lavas in volcanic rock are characterized by thick sequences of discontinuous pillow-shaped masses, commonly up to one metre in...

 and hyaloclastite

Hyaloclastite

Hyaloclastite is a hydrated tuff-like breccia rich in black volcanic glass, formed during volcanic eruptions under water, under ice or where subaerial flows reach the sea or other bodies of water. It has the appearance of angular flat fragments sized between a millimeter to few centimeters...

 indicating that the volcano

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 formed beneath ice

Ice

Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...

 or under a large lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

. The volcano comprises loose debris

Debris

Debris is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, in geology, large rock fragments left by a melting glacier etc. The singular form of debris is debris...

 as well as dikes

Dike (geology)

A dike or dyke in geology is a type of sheet intrusion referring to any geologic body that cuts discordantly across* planar wall rock structures, such as bedding or foliation...

 of basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

ic rock

Rock (geology)

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

 that intruded into the volcanic pile. Other tuyas in the area include Tuya Butte

Tuya Butte

Tuya Butte is a tuya in the Tuya Range of north-central British Columbia, Canada. It is a bit less isolated from other ranges than neighbouring Mount Josephine...

, South Tuya

South Tuya

South Tuya, also called Southern Tuya, is a tuya clustered around Tuya Lake in the Northern Cordilleran Volcanic Province in British Columbia, Canada...

 and Mathews Tuya

Mathews Tuya

Mathews Tuya is a subglacial mound in northcentral British Columbia. It is one of the six tuyas close to Tuya Lake. It has been partly glaciated so it is probably older than 10,000 years. The other volcanoes in the area include Tuya Butte, South Tuya and Ash Mountain...

, although most of the group of tuyas are un-named.

See also

• List of subglacial volcanoes
• Volcanism of Western Canada
  Volcanism of Western Canada
  Volcanism of Western Canada produces lava flows, lava plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes and maars, along with examples of more less common volcanic forms such as tuyas and subglacial mounds.-Volcanic belts:*Anahim...
  
  
• Volcanic history of the Northern Cordilleran Volcanic Province
  Volcanic history of the Northern Cordilleran Volcanic Province
  The volcanic history of the Northern Cordilleran Volcanic Province presents a record of volcanic activity in northwestern British Columbia, central Yukon and the U.S. state of easternmost Alaska. The volcanic activity lies in the northern part of the Western Cordillera of the Pacific Northwest...