 As a young man he farmed on the White Horse Plains, led a gold exploration party to Edmonton and then became the first post master for the Hudson's Bay Company at Fort Victoria, Alberta.Flett was an interpreter to the first Presbyterian mission to the northwest between 1866 and 1867.After serving as a delegate in the provisional government of Louis Riel during the Red River Rebellion, he became a missionary among the Ojibwa of Okanese Reserve, serving from 1873 to 1895.