Is it a hawk? a young eagle?

At first when I spotted this bird I thought it was an osprey, but have since found out they don't winter here.
It was the size of a large hawk or even a Bald Eagle.  Maybe it is a young Bald Eagle, but it has some light markings on both the top and bottom sides of the wing? I never got to see it's head, just its back side.

I am posting a bunch of photos to better make out all the markings on the bird.

Since it stayed in one spot for so long,  I thought it was attached to a string or maybe a fishing line?

Turned out it was just hovering above the dam outlet at Eureka Lake, MT.

Must have been a small rodent or something, the water is all froze over.