The first major incident was brought to the attention of External Affairs in January 1956. In a letter from Under-Secretary of State, R. M. Macdonnell, to A. D. P. Heeney, Canadian Ambassador in Washington, Macdonnell explained that the American company Alaska Freight Lines, Inc. had "brought men, equipment and fuel from Alaska to Norman Wells [with the] intention to construct several hundred miles of winter road in order to make deliveries to DEW Line sites." This, in fact, had taken place without any prior clearance by Canadian authorities. Macdonnell accordingly wrote that the company's plans constituted a "completely unauthorized operation in Canadian territory." In response to the incident, he instructed Heeney to "bring this matter orally to the attention of the State Department with a view to making clear the serious concern felt by Ministers." Acknowledging its delicate nature, Macdonnell further emphasized that the company's failure to observe the Canadian authorization procedure "is not only an embarrassment in itself but could, if exploited, become an irritant in Canada-United States relations out of all proportion to its size" (DCER, Vol. 23, 168).
A month later, in March 1956, Canada's Department of Transport saw Canadian participation passed over and the DEW Line agreement violated. As had been stipulated in the DEW Line terms, Canadian labor and material were to be used whenever feasable. When Ottawa proposed to transport DEW Line equipment and material through the Mackenzie River Valley , Washington rejected this scheme without further explanation and suggested direct transportation from Seattle to the DEW Line stations in the Arctic. Such an arrangement would have shut out any significant Canadian contribution regarding transportation. While the Minister of Transport complained that the United States did not provide sufficient explanation as to why the Canadian proposal was rejected, he further pointed out that "the line of argument advanced by the United States communication appeared to disregard the general principles which we thought had been agreed as applicable in the operational phase of the DEW Line, [â€¦] namely, use of Canadian materials and Canadian supply agencies wherever feasible" (DCER, Vol. 23, 171).
The question about Canada's effective protection of its jurisdiction and the exercise of its sovereignty in the Arctic arose again when it became known that mail going to and coming from the DEW Line stations would be channelled through U.S. Army posts in the United States. External Affairs expressed its concern about this "undesirable" situation and successfully argued that the Defense Department ought to reconsider its existing arrangement with the USAF and provide for a formula that included the Canadian Postal Service (DCER, Vol. 23, 173).