John Mortenson was born in Bismarck, North Dakota. Mortenson’s painter mother encouraged his early artistic ambitions by arranging formal training for him with his great Uncle Paul Rolshoven, a commercial and fine artist. In the course of his travels through Western Europe and Greece in the late 1960’s the young Mortenson reaffirmed his wish for a life in art. In 1969 he made the decision to move to Canada.John Mortenson worked and studied in Montreal, Winnipeg, Vancouver and Toronto, exploring different media and art forms. In 1988 he settled near the town of Roslin, Ontario where he set up Clear Creek Studio.
Ready for a different experience, he applied for the position of artist-in-residence at Bon Echo Provincial Park. Looking back over a difficult first year, he reflected on the challenges of space, light, and silence - the otherness of nature, and his need not to impose an interpretation, but to accept whatever nature had to offer. His work on this sacred ground was strongly influenced by the Group of Seven, whom he felt he had learned to know, years before, through his membership in the Arts and Letters Club in Toronto. A J Casson was a member during this time and John was privileged to paint side by side with him on many occasions. His paintings often reflect the unusual viewpoint favoured by Charles Comfort (who he also knew) or the less obvious subjects often chosen by Hagan. He paints Canadian subjects alternating with working holidays sketching in the South of France under different light in a gentler landscape.
In 1998 John was chosen along with fifteen other artists, five of which were members of the Group of Seven, to be included in a book called Massanoga; The Art of Bon Echo, an Archives of Canadian Art Series publication by Penumbra Press, Toronto. In 1999 John made the decision to move to British Columbia with his partner and settled on Vancouver Island.
He is currently enjoying painting the mountains, seaports and quaint villages of the West Coast of Canada as well as the California coast and the American South West .