Beynon was born 1888 in Victoria, British Columbia, son of a Welsh steamer-captain ("Captain Billy" Beynon) and a Tsimshian woman of Nisga'a ancestry. Although some sources describe Beynon as being himself Nisga'a or as being matrilineally Nisga'a, the truth is slightly more complicated. Beynon's maternal line leads back to members of the Laxgibuu (Wolf clan) of the Nisga'a nation, but members of his line had been moved from the Nass River to Port Simpson, British Columbia, the largest Canadian Tsimshian community, to fill a power vacuum there when nearly the entirety of the Gitlaan tribe (one of Lax Kw'alaams's "Nine Tribes") migrated to Metlakatla, Alaska, in 1887.
Beynon's maternal grandfather was the Tsimshian chief and Hudson's Bay Company employee Arthur Wellington Clah. Beynon was the only one of six brothers raised fluent in the Tsimshian language. When Mrs. Beynon's only surviving brother, Albert Wellington, died in 1913, William moved to Port Simpson to assume his uncle's hereditary title, Gwisk'aayn, in accordance with Tsimshian rules of matrilineal succession, making him chief of the Gitlaan tribe until his death.
Beginning in 1914, he was hired as a translator and transcriber by the anthropologist Marius Barbeau, then in the employ of the Geological Survey of Canada. Barbeau and Beynon's series of interviews with Lax Kw'alaams chiefs and elders in 1914-15 has been called by the anthropologist Wilson Duff "one of the most productive field seasons in the history of [North] American anthropology." In 1916 Beynon continued the same type of work, on his own, with the Tsimshians of Kitkatla, B.C., a trip which was marred by a measles epidemic and being shipwrecked for ten days on an uninhabited island with Chief Seeks of the Kitkatla tribe. As Beynon increased his facility with phonetic transcription and with his own people's traditions—which, as a formerly assimilated urbanite, he was quickly learning—he began to work more and more under his own direction. In the 1920s he worked with Barbeau with elders from the Kitsumkalum and Kitselas Tsimshian and the Gitksan nation, in and around Terrace, British Columbia.
From 1918 to 1924, Beynon worked extensively up and down the coast collecting museum artifacts for Sir Henry Wellcome, executor of the estate of William Duncan, the founder of Metlakatla, Alaska—where Beynon spent considerable time as Wellcome's local representative.
From 1929 until 1956, when he became ill, he continued to send Barbeau his own fieldnotes, covering every conceivable aspect of the culture and traditions of the Tsimshian, Gitksan, and Nisga'a peoples, with a special emphasis on carefully recorded oral narratives. His tour de force was a 200-page description of a four-day potlatch and totem-pole-raising feast in the Gitksan village of Gitsegukla in 1945. This has recently been issued in book form.
Wilson Duff has called the resulting thousands of pages of Barbeau-Beynon fieldnotes, now housed at the Canadian Museum of Civilization, "the most complete body of information on the social organization of any Indian nation".
From 1932 to 1939 Beynon sent the anthropologist Franz Boas approximately 250 transcribed narratives which have become the monumental "Beynon Manuscripts," now housed by the American Philosophical Society in Philadelphia.
In the early 1930s Beynon facilitated the immensely productive Port Simpson fieldwork of Boas's student Viola Garfield. Many pages of Garfield's voluminous field notebooks are actually filled out in Beynon's handwriting.
Beynon died in 1958 in Prince Rupert, B.C. Although he had spent most of his life earning his living in canning and fishing, like most of his fellow Tsimshians, he made as large and valuable a contribution to Northwest Coast ethnology as any professional anthropologist. His published and unpublished works continue to be an invaluable resource for the Tsimshian, Gitksan, and Nisga'a peoples.
Beynon, William (1941) "The Tsimshians of Metlakatla, Alaska." American Anthropologist (new series), vol. 43, pp. 83–88.
Beynon, William (1999) "Nda ckshun Tckaimsom dis Laggabula -- When Tckaimson and Laggabula Gambled." In: Alaska Native Writers, Storytellers & Orators: The Expanded Edition, ed. by Ronald Spatz, Jeane Breinig, and Patricia H. Partnow, pp. 44–47. Anchorage: University of Alaska.
MacDonald, George F., and John J. Cove (eds.) (1987) Tsimshian Narratives. Collected by Marius Barbeau and William Beynon. (Canadian Museum of Civilization Mercury Series, Directorate Paper 3.) 2 vols. Ottawa: Directorate, Canadian Museum of Civilization.
"B.C. Indian Authority Dies" (obituary for William Beynon). Vancouver, B.C., Province, February 11, 1958, p. 28.
Cove, John J. (1985) A Detailed Inventory of the Barbeau Northwest Coast Files. (National Museum of Man Mercury Series, Canadian Centre for Folk Culture Studies, Paper 54.) Ottawa: National Museums of Canada.
Duff, Wilson (1964) "Contributions of Marius Barbeau to West Coast Ethnology." Anthropologica (new series), vol. 6, no. 1, pp. 63–96.
Garfield, Viola E. (1939) "Tsimshian Clan and Society." University of Washington Publications in Anthropology, vol. 7, no. 3, pp. 167–340.
Halpin, Marjorie M. (1978) "William Beynon, Ethnographer, Tsimshian, 1888-1958." In American Indian Intellectuals: 1976 Proceedings of the American Ethnological Society, ed. by Margot Liberty, pp. 140–156. St. Paul: West Publishing Company.
Nowry, Laurence (1995) Marius Barbeau, Man of Mana: A Biography. Toronto: N.C. Press.