The halo on the mountain trees is a bit distracting... maybe a sharpening issue? Lovely scene and composition - just a minor detail on the trees...
There is a larger issue that cameraf4 alludes to: in the sky from the trees over the mountain and to the other side is a line of distracting artifacts. Sort of looks like clouds that have been covered.
The scene itself is very inviting. I particularly like the dappled light on the canoe and its prominence in the foreground. Step right in!