I need to correct some of my notes to this thread now that I've been to Steveston Village in BC and nosed around in C. Fox Smith fashion. There is no record of a Steveston Lumber Mill there, or anywhere else in BC. There were Salmon canneries in Steveston by the dozen but no major lumber mill. The Brittania Heritage Shipyard, referred to above, was never a lumber mill although there was probably plenty of wood being sawed there. This is curious because CFS also refers to Steveston as a port for shipping out "deals" (inexpensive planking) in another of her poems "Port o' Dreams." Maybe Danny McLeod can shed some light on this question, given his recent travels and research in the Vancouver, BC, area.
CFS also wrote the poem "Hastings Mill" which was focused on a well documented major lumber mill in neighboring Vancouver. However, she was resident in Victoria, BC, for much of her stay in the early 1900's and may have only visited the Vancouver area briefly.