Michael O'Leary said:
Sounds like one of the hypothetical defence plans from the 1920s, more Staff College exercise than reality based threat.
You are two for two Micheal, 2nd place to Geo.
Report No.2, Historical Section, Canadian Forces Headquarters:Canadian-American Defence Relations
1867-1914, Plans for Invasion of Canada
"United States Plans for Invasion of Canada
46. A series of War College papers dealing with attacks on Canada.
(a) USNA, war Dept, GS, War Plans Div, Classified Gen Correspondence, 1900-1920,
Box 20, File 8364-5, Maj J.M. Shaw, USMC, "Military Geography of the Provinces
of Manitoba, Saskatchewan, Alberta and British Columbia," n.d.
(i) This paper was prepared by a War College student of the class of 1912-1913.
(ii) The author says the US should immediately take the offensive in the West in the
event of war, destroying railway communications at Winnipeg and over the
Fraser River, followed by an occupation of the main towns."
Source: http://www.forces.gc.ca/dhh/downloads/cfhq/cfhq002.PDF
Edit to add:
"Buster Brown gained infamy after his death as the author of “Defence Scheme No. 1,” drafted in late 1920 and early 1921. This document laid out a defensive plan that called for a pre-emptive Canadian attack on the United States in the event of looming conflict. Buster Brown prepared this document in his role as Director of Military Operations and Intelligence (DMO & I) at National Defence Headquarters at the behest of his superiors, and it is arguably typical of military plans, prepared for a possible worst case, and admittedly unlikely to be used. This said, his ardent defence of its content, particularly the military personnel and materiel requirements that it entailed, has
caused him to be personally associated with it."
Source: http://www.army.forces.gc.ca/caj/documents/vol_08/iss_1/CAJ_vol8.1_16_e.pdf