Sargeant Bay Provincial Park boundaries were expanded in 2004 to encompass the entire drainage of Triangle Lake.
The official document is viewable on the BC Government website at:
https://www.bclaws.gov.bc.ca/civix/document/id/bills/billsprevious/5th37th:gov74-1:
BILL 74 — 2004
MISCELLANEOUS STATUTES
AMENDMENT ACT (No. 3), 2004
Protected Areas of British Columbia Act
32 Schedule C of the Protected Areas of British Columbia Act, S.B.C. 2000, c. 17, is amended
i) by repealing the description of Sargeant Bay Park and substituting the following:
SARGEANT BAY PARK
All those parcels or tracts of Crown land, together with all that foreshore or land covered by water, situated in Group 1, New Westminster District and contained within the described boundaries as shown on the Official Plan deposited in the Crown Land Registry as Plan 7 Tube 1940.
The whole park containing approximately 146 hectares (143 hectares of upland and 3 hectares of foreshore).
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This map shows the official survey details of the entire Park boundary as it exists today.