Il travaille au musée Glenbow de Calgary depuis 1956; d'abord archiviste jusqu'en 1967, il a ensuite exercé la fonction de directeur jusqu'en 1991; après sa retraite, il a été nommé conservateur émérite en chef. Les Gens-du-Sang l'ont désigné chef honoraire en 1967. L'université de Calgary lui a attribué un doctorat honorifique en . Il est devenu membre de l'ordre du Canada en 1975 «pour sa contribution à l'éveil et à la préservation de l'intérêt culturel dans l'histoire des Indiens des Plaines».
Publications
Ouvrages
A Blackfoot Winter Count, Glenbow-Alberta Institute, 1965 (OCLC605474).
Crowfoot, Chief of the Blackfeet, University of Oklahoma Press, 1972 (ISBN0-8061-1025-2).
Indian Tribes of Alberta, Glenbow-Alberta Institute, 1979 (ISBN0-919224-00-8).
Red Crow, Warrior Chief, University of Nebraska Press, 1980 (ISBN0-8032-1657-2).
History in their Blood: The Indian Portraits of Nicholas de Grandmaison, Douglas & McIntyre, 1982 (ISBN0-933920-32-6).
Big Bear: The End of Freedom', Douglas & McIntyre, 1984 (ISBN0-88894-506-X).
Gentle Persuader: A Biography of James Gladstone, Indian Senator, Western Producer Prairie Books, 1986 (ISBN0-88833-208-4).
Bibliography of the Blackfoot, (avec Lindsay Moir), Native American bibliography series, no. 13. Metuchin, NJ: Scarecrow Press, 1989 (ISBN0-8108-2211-3).
The Amazing Death of Calf Shirt and Other Blackfoot Stories: Three Hundred years of Blackfoot History, University of Oklahoma Press, 1996 (ISBN0-8061-2821-6).
Tom Three Persons: Legend of an Indian Cowboy, Purich Publishing Ltd, Saskatoon SK, 1997 (ISBN1-895830-08-7).
Tribal Honors: A History of the Kainai Chieftainship, Kainai Chieftainship, 1997 (ISBN0-919555-10-1).
Charcoal's World: The True Story of a Canadian Indian's Last Stand, Fifth House Publishers, Calgary, AB, 1998 (ISBN1-894004-20-5).
Firewater: The Impact of the Whisky Trade on the Blackfoot Nation, Fifth House Publishers, 2002 (ISBN1-894004-96-5).
The Vengeful Wife and Other Blackfoot Stories, University Of Oklahoma Press, 2003 (ISBN0-8061-3550-6).
«The Calgary-Edmonton Trail», Alberta Historical Review 7, no. 4 (Autumn 1959)
«Long Lance, Catawba-Cherokee and adopted Blackfoot», in American Indian intellectuals, coll. «Proceedings of the American Ethnological Society», West, 1978
«One Hundred Years of Treaty Seven», in One Century Later: Western Canadian Reserve Indians since Treaty 7, University of British Columbia Press, 1977
«History and Identification of Blood Bands» in Plains Indian Studies: A Collection of Essays in honor of John C. Ewers and Waldo R. Wedel, Smithsonian Institution Press, 1982