Thank you, everybody!
To echo TU's experiences, most lakes have at least some logs in them. One hike I went on last summer, the lake bottom was littered with nothing but huge rocks and trees, it was beautiful.
I think I'm going to turn this into a series looking at the same landscape but in all the seasons. Next up will be summer. I'll probably need to make the underwater terrain more interesting since the foreground won't be "hidden" by the water.