Named after cattle rancher "Charlie" Semlin. Charles Augustus Semlin (1836 - 1927) was born near Barrie, Ontario; he came to British Columbia in 1862 to look for gold, but found work with Chief Factor Cornwall at Ashcroft Manor. With Philip Parke, he bought the Cache Creek Hotel, and was first Postmaster at Cache Creek. Semlin established the Dominion (cattle) Ranch in 1870, and entered politics in 1871, winning Yale in that year's general election; defeated in 1876, re-elected 1882; Leader of the Opposition, 1884; elected Premier 12 August 1898; retired 27 February 1900. Died at his ranch 3 November 1927.
Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office