Coleman was fascinated by mountains and he was a keen alpinist. In 1888, while in the Rockies, he wrote that he was "…in search of high mountains." He explored, prospected, climbed, and made geological and geographical maps in the Canadian Rockies as early as 1884 and continued this activity periodically until 1908, paying his own way since Provincial Geological Surveys had not yet been established. He recorded his findings in field notebooks, reports and journals, and in a book, The Canadian Rockies: New & Old Trails (1911).
Coleman painted mountains throughout his life. The geologist’s keen observations were brought to bear in his sketches and watercolour paintings of mountains, glaciers, waterfalls and valleys from across Canada and around the world. He, like the Impressionists in France and the Group of Seven members in Toronto, practiced "plein air" painting.
