"An attempt at transposing the 2D-styled Alpine skybox into a 3D skybox. Includes a rough breakdown of the process. I ended up polishing this for a wallpaper, enjoy:

http://img.maxofs2d.net/source/tf_loghouse_alpine_2560.jpg
http://img.maxofs2d.net/source/tf_loghouse_alpine_1920.jpg

The RED Pyro is there as the only flashy thing of the whole scene, so you can easily get a sense of scale. The shot with the Pyro at the foreground is also there to show how the mountains look like when they're not the focal point.

Source files (including PSDs) and compiled assets available over here:
http://source.maxofs2d.net/index.php?dir=models/terrain_alpine_default"