One of Armstrong's largest watercolours, the scene depicted here may be on one of the tributaries of the Nipigon River. The figure seated in the left foreground with a feather in his cap also features in Armstrong's 'Fort William from Indian Camp' in the Royal Collection at Windsor (for which see D. Millar, The Victorian Watercolours and Drawings in the Collection of Her Majesty the Queen, I, London, 1995, cat. no. 136, RL32385).
The son of a Royal Irish Artillery officer, Armstrong studied art in Dublin and served his apprenticeship as an engineer on the Irish and English railways before emigrating to Toronto in 1851. He was a partner in the firm of Armstrong, Beer & Hime Civil Engineers, Draughtsmen and Photographers. He travelled to Lake Superior in 1859 and from then on took advantage of surveying work to travel and sketch extensively in lands then unsettled by Europeans. He took particular interest in the native populations of the northern plains, such as Assinboin and Sioux, glimpsed in the years immediately prior to their confinement to reservations. His sketches from his travels in 1859 to Fort William (now the city of Thunder Bay) were worked up into watercolours and presented to the Prince of Wales on his visit to Toronto in September 1860, these latter watercolours now at Windsor.
For a survey of Armstrong's art and life see the exhibition catalogue 'William Armstrong 1822-1914 Watercolour Drawings of New Ontario -- from Georgian Bay to Rat Portage', Thunder Bay Art Gallery, 1996.