Here's that Isabella River picture with the lines drawn on it. Notice that the canoe is placed at the lower left intersection, while the leading lines take you to the upper right intersection (red circles). Also notice that the horizon lies basically along the upper horizontal (blue) line.
... it was actually taken just a little south of the actual portage... we landed at the wrong spot, headed toward Isabella Lake. Joined the real portage via the hiking trail. But, yes, it was taken in that general area.