Yep it is and it smells too!! We too are knee deep in mud and all of mine came in today looking like this!! - got to go back out soon to remove fleeces and try and clean them up some more......
(PS I'm not nearly as fat as the coat!!)
lol! I love greys, they seek out the worst mud they can find!
Mine looked like that last summer 2 days before a competition, he was turned out naked in a dusty field and it drizzled so he rolled in the dust. He looked like an appaloosa!