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BC Court of Appeal Affirms the Western Boundary of Treaty 8 is the Arctic-Pacific Divide

Reading Time 6 minute read


Indigenous Bulletin

On May 19, 2020, in a split decision, the Court of Appeal affirmed the lower court decision regarding the location of the western boundary of Treaty 8, finding it is the height of land along the Arctic-Pacific Divide, and not the more easterly boundary of the height of the Rocky Mountains asserted by British Columbia and a number of non-Treaty 8 First Nations (West Moberly First Nations v. British Columbia, 2020 BCCA 138).

The decision rules on a long-standing dispute between Canada and the province as to the location of the boundary. The Court affirmed the view shared by Canada and a number of Treaty 8 First Nations that Treaty 8 includes approximately 48,000 square miles west of the Rocky Mountains in north-central British Columbia, which BC and a number of other First Nations asserted were not within the Treaty territory.

The decision also comments at length on treaty interpretation and the law of declaratory relief.


Treaty 8 is one of eleven numbered treaties in Canada, described by the Supreme Court of Canada as “one of the most important of the post-Confederation treaties”.  It was entered into in 1899 in order to open up the west for settlement and access during the Klondike gold rush. It covers land in northeastern British Columbia, northern Alberta, northwestern Saskatchewan and southern Northwest Territories. A total of 39 First Nations have signed or adhered to Treaty 8, including eight in British Columbia.

Treaty 8 describes the location of the western boundary as “due west to the central range of the Rocky Mountains, thence northwesterly along the said range to the point where it intersects the 60th parallel of north latitude”.

Since at least as early as 1909, the location of the western boundary of the Treaty 8 lands, and specifically what is meant by the “central range of the Rocky Mountains”, has been in dispute. This is, in part, due to an apparent discrepancy between the map (below) attached to Order in Council 2749 (1898) and the wording of the Treaty.

Indigenous Map Treaty 8-1

BC and three non-Treaty 8 First Nations with claims to the disputed territory argued at trial that the “central range of the Rocky Mountains” refers to the height of the Rocky Mountains, whereas Canada and the Treaty 8 First Nations asserted the boundary is the more westerly Arctic-Pacific Divide (or watershed). The two competing boundaries are shown on the following map, taken from BC’s Response to Civil Claim and included as Appendix D to the BC Court of Appeal decision.

Indigenous Map Treaty 8-2

The Court of Appeal’s Decision

In a split decision, the BC Court of Appeal affirmed the decision of the BC Supreme Court and found the western boundary to be the more westerly Arctic Pacific Divide.

In the course of its ruling, the Court offered guidance on the law of declaratory relief and treaty interpretation. 

Declaratory Relief

The first issue on appeal was whether it was appropriate for the Court to make a declaration on the location of the western boundary in the absence of a “live issue” between the parties.

The majority found the trial judge had the discretion to grant declaratory relief (at para. 357), whereas the dissenting judge disagreed noting it is unclear what legal rights the declaration would affect. The declaration would therefore have no practical utility in resolving the scope of the parties’ rights (at para. 100). The majority rejected this view, noting “the proposal that associated rights must be litigated in tandem with a declaration such as this represents an all-or-nothing approach to accessing declaratory relief. This is not only inconsistent with the jurisprudence, but fits poorly with the larger public policy context of this case” (at para. 352).

Principles of Historical Treaty Interpretation

Both the majority and dissent relied and expanded upon the seminal authority on historic treaty interpretation, R. v. Marshall [1999] 3 S.C.R. 456, in which Justice McLachlin (as she then was) summarized the governing legal principles.

The dissenting judge was of the view the trial judge failed to consider: (i) the meaning of the Treaty as a whole before turning to the other (extrinsic) evidence of the intent of the parties to the Treaty; (ii) the intentions, understandings and interests of the Indigenous signatories; (iii) the original signatories understanding of the boundary clause as it related to geographical knowledge at the time; and (iv) the honour of the Crown in interpreting historical conduct and intention. 

While the majority agreed with the importance of each of these elements of treaty interpretation, they disagreed that the trial judge erred in their application.

  • Historical treaties must be interpreted in their entire context: The wording of a treaty’s text need not be considered before turning to extrinsic evidence when determining the common intention of its signatories or adherents. Even when there is no ambiguity in the treaty text, extrinsic evidence is important to the interpretative exercise (at paras. 366-368).
  • The intentions, understandings and interests of the Indigenous signatories were properly considered: While the courts have recognized the importance of considering the view of Indigenous parties when interpreting a treaty, this requires evidentiary support. As the majority recognized, the trial judge considered the limited evidence on the intention of Indigenous parties and decided this evidence was not relevant to the interpretation of the boundary location (at para. 403).
  • Reliance on modern day geography supported the trial judge’s ultimate conclusion: As in Marshall, historical treaties are to be interpreted in their historical context. While the trial judge referenced some modern geographic evidence, he nonetheless interpreted the Treaty in its historic context, also relying on evidence from the nineteenth century (at paras. 406-408).
  • Reliance on the honour of the Crown was premature: In Marshall, the Court held that “[i]n searching for the common intention of the parties, the integrity and honour of the Crown is presumed”. The dissenting judge found that had the Crown intended the more westerly boundary it would affect the rights of Indigenous groups within the disputed territory, who were not adherents to the Treaty, and who were not notified or consulted. In her view, this supported an interpretation that the boundary is the narrower, more easterly one. In contrast, the majority found the interpretive principle of the honour of the Crown was not relevant to the historical facts of what Canada intended and what steps the Treaty Commissioners took. They found “the honour of the Crown is not applied to rewrite history. It should not be used to retroactively alter the promises the Crown actually made to Indigenous peoples to make these promises more honourable”. Rather, the honour of the Crown “requires the Crown to act in a way that accomplishes the intended purposes of treaties and solemn promises it makes to Aboriginal peoples” (at paras. 415-418).

The majority ultimately concluded the trial judge’s findings of fact supported his conclusion that the boundary was the more westerly Arctic Pacific Divide, and were owed deference.


In reaching its decision, the Court observed that a declaration regarding the location of the western boundary of Treaty 8 does not determine the substantive treaty rights of the plaintiffs or other Treaty adherents, but clarifies the geographic scope of the Treaty territory, a dispute between the parties for over 100 years. 

The split decision also highlights the deference owed to the fact-finding role of the trial judge in complex cases. This case involved 61 days of trial over two years with a record that included over 1500 pages of reports from 11 different experts. Given the depth and breadth of evidence, the majority cautioned against appeal courts stepping into the shoes of the trial judge on findings of fact.



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