Blue stoneware bowl from USA marked ND?

Hello all.  Recently picked up a set of plates and bowls all the the same maker's mark ND.
After doing extensive research I cannot find a match.  I saw some ND marks here on the site but none seem like the one.
Would anyone happen to know who this maker is?  Many thanks.  I am thinking mid century american.

NaomiM wrote:Might be a CN or NC mark. I’m afraid most of us are based in the U.K. and unfamiliar with US marks

Ah thanks! yeah well I am only guessing it is american, but really do not know. Sadly, there are probably thousands of ceramicists out there so tracking it down it almost impossible. Thanks again.