Another mudder on this site and I discovered a nice spot along the Patapsco River last August, south of Baltimore, close to I-695 , just off of Hammonds Ferry Road. Attached photo will give you the idea. I got waist deep in it last summer. There's some brush/undergrowth/trees to hike through (not far though) from the riverbank, but it's pretty much completely hidden from view....easy clean up in the river. It's pretty much public access, no private property issues to worry about. Parking is easy, and there's a Park'n'Ride lot nearby too. Not perfect mud, but it's not bad, either.
It has a VERY hard to find combination of decent mud out of view, easy cleanup, no privacy issues, and a place to leave the car.
Posting this to see who might be interested in meeting up there when weather warms up, open to meeting up somewhere ahead of time for those interested in that.
Hey there, I also live in the area and have been wondering if there was any good location on the Patapsco for this. I've never been mudding before. I don't know that I'll be able to do any meetup but it's nice to hear that there's a good enough area for it nearby.