Tom Thomson at Achray in 1916, Appendix
Abstract: There are several Tom Thomson sketches that have the correct feel to be of Grand Lake and yet are sufficiently generic to preclude location, especially considering the vegetation changes over the last 100 years. They are included here.
Lake in Autumn
In an article (Spotlight on Two Tom Thomson Masterpieces) in the National Gallery's magazine, it is suggested that this sketch was "not likely painted out of doors" and it is an imagined colour scheme and that this colour scheme influenced the transition of the Jack Pine sketch to the Jack Pine studio painting.
We see nothing in this sketch to suggest that it was not painted out of doors nor do we see problems with the colour scheme. Green tints in the sky at dusk are not uncommon. Whether this sketch influenced the colour scheme of the Jack Pine studio painting is a different issue. Indeed, many of Thomson's sketches exhibit a greenish tint to the sky to a greater or lessor extent, e.g.: