Dark Contrail [Chemtrail?] over Las Vegas

    This was a dark tunnel-appearing patch of sky over Las Vegas around Eastern and Sunset Rd. about 3 PM.  I shot it with my Samsung phone. I have never seen something like this, it appeared to be an exhaust from a diesel source, like a smoke trail, but there were was nothing in the sky that I could see that could have accounted for this dark tunnel-like patch of sky.  There were quite a few contrails/chemtrails in the sky at this time.  For some reason, my phone unexpectadly just quit working as I was filming this.  There is a small spherical object that appears in the video, that I did not see as I was shooting.  I cannot classify either the dark contrail/chemtrail or the small white object that appears in the video.  As always, you can be the judge.