Cloud Phenomenon

Before going out late mid-morning, I stood on my driveway and noticed that cloud was covering just a thin band throughout one area of the sky. I couldn't see the beginning or the end of the phenomenon, it looked like the arch of a rainbow, but in cloud. Too thick (and didn't fade) so it couldn't be a skywriter.

I'm happy to also say that these pictures are completely untouched by Photoshop :)