Grasmere (settlement) identified in the 1930 BC Gazetteer. The dual name "Grasmere (Flagstone Post Office)" adopted 2 March 1948 on Columbia River Basin manuscript #50. Form of name changed to Grasmere (community) 14 January 1983 on 82G/3. Form of name changed to Grasmere (locality) 29 November 1984.

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

Flagstone Post Office was opened 15 June 1910. Post Office name changed to Grasmere 2 October 1958, as petitioned by the Women's Institute, to conform to the name of the surrounding community.

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

"Earlier named "McGuire" after Howard McGuire who arrived in the district in 1898. In 1922 when a new school was built, every pupil submitted a new name. A draw was held, and the entry which was picked was that of young Warren Lancaster, who had proposed Grasmere."

Source: Akrigg, Helen B. and Akrigg, G.P.V; 1001 British Columbia Place Names; Discovery Press, Vancouver 1969, 1970, 1973.

The traditional name for this site is ?akink'umtasnuqti?it, pronounced a-kin-koom-thas-nooq-thi it. [meaning/significance not provided] (April 2006 advice from Janice Alpine, Ktunaxa Language Program)

Source: included with note