The answer is yes but it varies by State. Phil will probably just refer you to me as I am the source for many of his Texas mudpit locations came from. Florida is a work in progress but there is a lot of tidal mud there and several mudmen around who might share a location or two. The real gem is Georgia around Sandersville however if you're looking for creamy white kaolin quarry mud. There is a possible mudpit in Alabama as well.
Note however that most deep mud mudpits will involve trespassing. Message me if you want further details.