The image below was taken by Mathieu Dupuis.
Where is this?
The location is:
The Saint Lawrence river, Quebec
On this website, I found the exact same photo with the caption:
Fall foliage on the Saint Lawrence River.
It is difficult to pinpoint where this photo was taken along the river exactly as the river is 1,197 km long.
This article provides some places where you can view fall foliage on the St Lawrence river.