Forests of British Columbia by H.N. Whitford and Roland D. Craig ; under the direction of Clyde Leavitt. Published in Ottawa, Canada by the Commission of Conservation in 1918. Available online at https://archive.org/details/forestsofbritish00cana/mode/2up
An extract is available here
Powell Forest by M.W. Gormely, the 1931 Forest Survey #27 that describes what eventually became Tree Forest Licence 39. Available as a pdf here
Powell River Company Digester Magazines. 1922-1965. Kindly scanned and published online by the qathet Museum and Archives here.
As I remember it, by Elsie Paul kindly provided to read online by Raven Publishing here