Precipitation runoff and glacier meltwater from the mountain drains into tributaries of Mosley Creek, thence Homathko River and ultimately Bute Inlet.

The first recorded ascent of Blackhorn's summit was made in August 1932 by Henry Snow Hall and Hans Fuhrer.

[7][8] The Blackhorn name was submitted for consideration in April 1933 by Henry Snow Hall (1895–1987), Harvard Mountaineering Club, following his 1932 ascent.

[9] Hall wrote: "I have suggested the names Whitesaddle and Blackhorn for the two peaks which are prominently visible down the Homathko valley from the automobile road passing Tatla Lake.

[11] Most weather fronts originate in the Pacific Ocean, and travel east toward the Coast Mountains where they are forced upward by the range (Orographic lift), causing them to drop their moisture in the form of rain or snowfall.