100 Mile House (Post Office) adopted adopted 3 March 1955 on 92P, as labelled on BC map 3G, 1919. Incorporated as The Village of 100 Mile House 27 July 1965. Re-incorporated as a District Municipality per Letters Patent 13 June 1991, called District of 100 Mile House. 100 Mile House (District Municipality confirmed 8 November 1991 on 92P/11.

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

100 Mile House Post Office was opened 1 February 1916, named in association with the long-established settlement here, grown up around the original road house, located 100 miles north of Lillooet on the Cariboo Road of the 1860s.

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

The old road houses (for meals, beds and changing horses, with perhaps a store & post office) on the Cariboo Road north of Clinton, were named for the distance from Lillooet, whence the road originally was constructed in 1862-63. Although the wagon road up the Fraser Canyon to Spences Bridge and across to Clinton was opened soon after, the names [of the road houses] remained unchanged.

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

In 1912 the Marquess of Exeter purchased an extensive ranch here. It was later managed by his son, Lord Martin Cecil [president of Bridge Creek Estate Limited], who died in 1988, aged 78.

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