Page 9 on the following link states that Charles A. Roulston was with the Rocky paper from 1917-1918.
http://docs.google.com/viewer?a=v&q=cache:wPmA5FL1Pn0J:w...If you google the book 'Alberta Newspapers 1880-1982' Roulston was at a number of Alberta newspapers and the years are stated.
Peel's Prairie Provinces has various Alberta newspapers indexed and you may want to try to search them.
http://peel.library.ualberta.ca/index.htmlHope this helps.- Wilma