I'm talking the 'Con, the Hammers, portions of Tellico (i.e. Helicopter Pad, GuardRail) or the super rutty and always muddy trails there, hard stuff in Moab (i.e. Dump Bump, Potato Salad Hill, Double Whammy) stuff like that. Basically anything rated 4 or better on 1-5 scale.
Don't think there is any Hardcore sand.
For mud,it'd have to be a big ass bog. Tractor tires, blown big blocks, full-size trucks are the only things that get through.