A touch too much blue, and the sky looks a little grainy. Everything, except the sky, appears to be under-exposed too. The subject fits the challenge well, and the composition is okay.
Very nice composition with the foreground tree and the lake. Mt St Helens itself is a bit un-contrast-y and appears to be behind lots of haze. On the right side of the mountain, I can see lots of jagged lines which suggests oversharpening or maybe resized wrong. The sky above has noise.
Great photo here. I am curious about your processing on this one as I find the blues and cyans confusing. The sky is cyan, the mountains are blue, yet the reflection of the sky in the water is blue. I would think that the sky would be blue and the mountain cyan, naturally, and it would balance out the colors in the photograph better. 9