This is another picture I took while out in western Oklahoma. The sun was rising through a mist that morning and made for some interesting shots across the numerous canyons. I used a graduated filter.
Nice use of layers in the hills to add depth to the image.
You might try a Shadows/Highlights correction to extract the lower silhouette of the hill to add a bit more depth to the image. While in S/H use the mid-tone slider too to lower contrast.