MudSlogger said: Next places to look are creeks, ponds, rivers, swamps. Anywhere near sources of water should have thick, slimy, creamy mud.
Sadly, that's not necessarily the case, but it's a good start. Some areas simply have rockier beds. Finding decent "mud" here in PA is quite hard because there isn't much in the way of silt, just "very small rocks", which we all know, float on water; like churches.
Now, I know everyone's living situation is different, but I think one of the best ways to do it, is the simplest; make your own.
i would recommended to go on a road trip there nothing better than listening to music (especially 80s music) while you search for a mud pit to claim as your own or maybe its just because the hunt for a pit is half the fun.
what ever you decide to do just remember to take care of yourself.
Definitely look for creeks and ponds - not only do they often have mud nearby (unless you've had a lot of rain lately, in which case any mud is likely underwater), but they also should have places to wash off after. Sometimes creeks are rocky and not muddy, but you never know until you explore. Start off by going off trail down a creek, if there's a nature preserve or bike trail that goes near a creek/pond, bring a few changes of clothes, and have fun exploring!
Moving water is a big plus. Accumulated silt that piles up in turns and elbows of streams or rivers in flat country is great. That's not always easy to come by where I live as everything is rock just beneath the shallow surface soil. Bottom line is to follow the water.