Lake or marsh?

This is the furthest we've walked this year, heading deeper into the forest, though we are still on a forestry road.
The pictured marsh ends where the water drains into a fairly small steep-sided valley, just to the right, off-camera. There, beavers decided, was the ideal spot to build a dam, which they did. It created a small lake, but then, driven by instinct, they built the dam higher, and to do that they had to build it wider. For the last twenty years there's been the biggest beaver dam I've seen. It's at least 50 meters wide and two meters high and it made this marsh into a lake. In turn that killed all those dead trees you see. The local land-owner is not happy with that and the dam has been blasted open at least a couple of times in these twenty years. But beavers always return and always repair the dam. In the end the collective persistence of the beavers will win, because they'll still be here when the forester is dead.
From my blip point of view this is one of the few places where you get a view over and of the forest. Mostly you (literally) can't see the forest for the trees.
The extra shows a eurasian red squirrel in our garden.  This one has been feeding off the bird feeders, and then dropped to the ground to grab the bits it had dropped. Then it had a thoughtful moment, sitting there and contemplating...