I was lucky this morning. I went out so I could try shooting the grain elevator and having a forest fire in the same image. This image was shot right after the sun had cleared the horizion.
The background looks like clouds. This is actually smoke from the forest fire. The fire is called the High Park Fire. There is no containment.
When the sun came up there was a small band of clear sky near the horizon. I got the golden glow when the sun was shinning through the clear sky. I have several other images here on Pbase. You can see how much the smoke is in the area around Roggen. Roggen is northeast of the Denver metro area.
You could not see the smoke plumes at all. Sat, you could see the plumes from the Denver area.