Finalizing the Sky
Using the same limited palette of warm cadmium colors, I began with a mixture of white tinted with yellow to bump of the light of the setting sun. It needed an impasto effect. Then I refined some of the light streaks so they were interesting and interactive. At this point, it's all about the shapes of the light.
A red-orange glaze over the mountain where the sun sets gives the glow I am looking for.
I developed the large tree mass even more, adding some good dark accents. I also developed the other trees along the river bank.