Mammatus clouds spotted

In Lake Mills tonight after a huge storm passed through, I was drawn to these clouds I have never seen before. After searching on the interwebs we found them to be Mammatus clouds or something that seems to be...

Either way, these clouds formed in front of our eyes and moved at a very high pace. The clouds grew and split as they hauled sideways across the sky. After the clouds blew over, Craig and I went down to the lake (Rock Lake) because I wanted to look west to see what the sun was doing. Mr. Sox stayed behind as we scoped out what mother nature left behind in all her beauty.