McArthur Lake adopted in the 5th Report of the Geographic Board of Canada, 30 June 1904; also creek and pass, in association with Mount McArthur. Form of name changed to Lake McArthur 6 June 1952 on 82N/SE.

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

"After J. J. McArthur, DLS, who discovered the lake." (18th Report of the Geographic Board of Canada, 31 March 1924); later a member of the International Boundary Commission (1917-1924).

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

"After James Joseph McArthur, DLS; from Aylmer, Quebec; commissioned as a Dominion Land Surveyor in 1889; did extensive survey work in BC and NWT; discovered this lake; on International Boundary Commission (Yukon-Alaska ?). Mt. McArthur in Yukon; on photo-topo surveys along CPR main line and west to 116º10'W. McArthur surveyed the area in 1891-92 and his reports are in the Annual Reports of Department of the Interior for those years, although he makes no mention of his discovery." [might be looking in the wrong volume: see also Lake O'Hara - presumably McArthur had "discovered" these lakes in 1887, per Ottawa note, below].

Source: Provincial Archives of BC "Place Names File" compiled 1945-1950 by A.G. Harvey from various sources, with subsequent additions

After James Joseph McArthur, DLS, (1856-1925) of the Dominion Topographical Survey, who discovered both this lake and nearby Lake O'Hara.

Source: Akrigg, Helen B. and Akrigg, G.P.V; British Columbia Place Names; Sono Nis Press, Victoria 1986 /or University of British Columbia Press 1997

Named after James Joseph McArthur, surveyor of meridian lines and base lines in the NWT in 1881. In 1887 he used phototopography for the first time in the Rockies. He worked on the International boundary from 1901-1917 and was a Commissioner until his death in 1925. (Ottawa file 82N/8 Volume 1).

Source: Canadian Geographical Names Database, Ottawa