I know I made a post similar to this a few years back, and it might be a little late in the mudding season to be asking this. One of my best friends in the mudding scene and I have experienced minimal luck these past few years in finding new mud spots in Massachusetts especially. We value spots that are largely off the beaten path in terms of being on the more private side, rather than taking a chance with spots that are within public view. Each spring and summer, we have scouted places that seem swampy/marshy/boggy on maps, only to come up short in one way or another - whether it be with little mud/sediment, or with little privacy.
We've visited the mud flat in Dartmouth, MA many times, are always checking the community mud map linked on Quicksand Fans, and we're on the fence about quarries. I think these were suggestions that were brought up by others the last time I made a post. Also, one of my other longtime marshes is no longer useable because of safety concerns, so that's been off the list. I'm just curious to see if anyone has any newer leads in New England that guarantee enough privacy and can (ideally) provide a deep sink.
I am based in Metro Boston but am open to driving out a ways if a spot is promising.