The green glowing sky above here is caused by a phenomena analogous to the northern lights known as airglow. Airglow is caused by the light of electronically and/or vibrationally excited atoms and molecules. Green light from excited oxygen atoms dominates the glow. Below the airglow is a bright layer of light pollution coming from natural gas being flared off on a new oil and gas field to my north near Grover.
Image Notes: I tried to keep the colors as true to life as possible here to not lose the delicate airglow. I took two frames to extend the two-track foreground.