If you have Photoshop, here area couple things worth trying:
1- Copy the layer and change the blending to overlay. Erase the front snow bank and creek with a 100% eraser and the trees on the right side (up to the canopy) and shoreline on the right with a 50% eraser. Set the overlay layer transparency to 50%. Here’s what that looks like:
The idea here is that it adds branch contrast and darkens the sky without altering the colors too much.
2- Copy the layer and change the blending layer to lighter color. Increase the image's brightness and reduce the contrast until you have branch detail in the area over the creek (and the trees to the right, we'll call this, collectively, the central branch detail.) I'd caution against losing the fog too much, though. Once you're happy with the results of that one area, which may require dropping the layer transparency, erase the over-exposed area from the top layer with a large brush at around 55%. This will take three passes to fully erase an area and going in stages will let you blend the perimeter more easily later. After you have the bright areas erased, refine the perimeter with progressively smaller brushes until you've basically erased everything except the central branch detail. Then adjust layer transparency and refine the erased areas more until it looks natural. With that complete, copy the layer you just refined and jack up the contrast as much as possible. Change the transparency to Overlay and run a high-pass filter at 3 to 5 (I used 4), checking the results for taste. Drop the transparency to a point where it looks good (I had the bright layer at 85% and the overlay layer at 15%, and in general find that techniques like this work best when the two layers’ transparencies add up to 100%.) The aim here is to bring out branch detail and contrast, which will be somewhat lost by the previous steps. The transparency reduction should give you nice branch reveal without destroying the fog.