The Black Tusk

Black Tusk is a remarkably abrupt pinnacle of volcanic rock located in Garibaldi Provincial Park of British Columbia, Canada. At 2,319 metres above sea level,^[1] the upper spire is visible from a great distance in all directions. It is particularly noticeable from the Sea-to-Sky Highway just south of Whistler, British Columbia. Distinctive and immediately identifiable, the Black Tusk is among the best known mountains in the Garibaldi Ranges of the Coast Mountains. The volcano is part of the Garibaldi Volcanic Belt which is a segment of the Cascade Volcanic Arc, but it is not within the geographic boundary of the Cascade Range.

Indigenous

Black Tusk Mountain, or t'ak't'ak mu'yin tl'a in7in'a'xe7en is a mountain considered "very sacred" by the local Indigenous Sḵwxwú7mesh. It is known to them as the "Landing Place of the Thunderbird", home of the legendary Thunderbird. The rock was said to have been burnt black by the Thunderbird's lightning.^[2]

Geology

Black Tusk is considered to be the remnant of an extinct andesitic stratovolcano which formed between about 1.3 and 1.1 million years ago.^[3] Following glacial dissection, renewed volcanism produced the lava dome and flow forming its summit about 170,000 years ago. According to Natural Resources Canada, Black Tusk was "perhaps the conduit for lava within a cinder-rich volcano. The loose cinder has eroded, leaving only the hard lava core." ^[4] The exposed lava rock of the core is loose and friable. It is also black, giving the mountain its name and character. Cinder Cone, to the east of The Black Tusk, produced a 9-km-long lava flow during the late Pleistocene or early Holocene.

The mountain currently hosts two significant glaciers, in large cirques carved into the northeastern and northwestern flanks of the broad cone below the lava pinnacle. Both glaciers start from about 2,100 m (6,900 ft) and flow northwards to below 1,800 m (6,000 ft). The glaciers are heavily covered in rocky debris due to the crumbling nature of the Tusk's rock.

Black Tusk is a member of the chain of volcanic peaks that run from southwestern British Columbia to northern California. The peaks formed in the past 35 million years as the Juan de Fuca, Gorda and Explorer plates to its west have been subducting under the North American Plate at the Cascadia subduction zone.

Recreation

Black Tusk's lower flanks and south summit are a popular backcountry hiking and scrambling destination. Most hikers approach from the Taylor Meadows campground to the south near Garibaldi Lake, although there is a second route from the north that travels by way of Helm Lake.^[5] A third option approaches from the west, from a microwave relay tower located at about 1,800 m (6,000 ft) on the western flank, which is reached by a dirt road from the Cheakamus River valley.

The upper summit area at the top of the lava column can only be reached by scrambling up a short but exposed rock chimney to reach the south summit.^[6] The true summit, only about a meter higher, lies just to the north across a precipitous drop. It is rarely climbed, requiring a rappel of about 10 m (30 ft) into a notch followed by a loose and dangerous reascent up the crumbling lava. On the northern side of the north summit stands an isolated and intimidating rock formation known as the "Bishop's Mitre", which is rumoured to be unclimbed.^[7]^[8]