Lenticular clouds, often looking like flying saucers, may form as moist air flows over a mountain range. Here, lenticulars have formed on the downwind side of the Front Range near Boulder. (This photo took 6th place in Digital Photography Review’s Aleatoric Forms: Open Subjects from Abstract Mediums challenge.)
5280 Lens Mafia 
I’m not sure I’ve ever seen a formation quite like this one. This is a wicked cool shot.
I think your Colorado clouds are cooler than our Iowa clouds. Wow.
I have very much enjoyed the amazing skies of the prairies. But to be honest, I have never seen anything like what we experience regularly here along the Front Range. For a photographer, it is like shooting fish in a barrel.
What’s with the subtle ray-like streaks emanating from the middle of the far horizon?
There’s a meteorological term for those: “God beams.” In any case, I think you are picking up on the central mystery of this photo: Why are the God beams emanating from the east as the sun is setting on the opposite side of the sky? Usually God beams are associated with the setting sun, often the result of shadowing due to topographic features. But what’s up with these? I assure you that those beams are real. All I did was boost the contrast a little to get them to stand out. And I have never seen anything like it. That’s why I think this really was a manifestation of an alien invasion…