There are many places to go Mudding in Memphis, Tennessee. Sorry that I have not been able to udate in a while, but one of the larger and well known places the "Bottoms" is closed right now but I am receiving the info. second hand and haven't been down there in a while so I might be wrong. Anyways if they reopen you will find trails to go on and usually plenty of mud. But, this trail does not have the name "The Bottoms" for nothing, if you are not very good or if you are just beginning with 4X4's, you can easily get stuck.
There is also the Sex trails, and plenty of other places to go including some parks in which you can trail ride or mud.
I have recently been to the Bolten Bottoms and had fun.The highlight of the trip was the mud but the trails are not very long and didn't offer many obstacles.