Lewis Ankeny McArthur (April 27, 1883 – November 8, 1951), known as "Tam" McArthur, was an executive for Pacific Power and Light Company. He was also the secretary for the Oregon Geographic Board for many years and the author of Oregon Geographic Names. His book, now in its seventh edition, is a comprehensive source of information on the origins and history of Oregon place names. It is a standard reference book in libraries throughout Oregon and the Pacific Northwest. Tam McArthur Rim in the Cascade Mountains is named in his honor.