I think I was waiting for this one.
I was driving the motor home on I80 towards Wendover NV this evening
About 35 miles from there off to the south maybe 70 miles was some type of a massive black explosion that looked and developed just like the abomb testing in the 50s and 60s. It was a slow developing mushroom cloud type of smoke rising up. And to top it off it influenced the high clouds just as you see an abomb does forming the thin lens type of cloud. I have a few long shot pictures in my sony camera that look quite impressive.