Originally a commercial artist, Thomson fell in love with the forests and lakes of Ontario's Algonquin Park and devoted himself to rendering the north country's changing seasons in a series of colourful sketches and canvases. Dividing his time between his beloved wilderness and a shack behind the Studio Building near downtown Toronto, Thomson was a major inspiration to his painter friends who, not long after his death, went on to change the course of Canadian art as the influential - and equally controversial - Group of Seven.