Sorry, I don't know Mountainside Pottery....nor John Kovacs.
But the interior stilt marks are because the pottery was stacked in the kiln...plate upon plate and bowl upon bowl, and that it was glazed before firing.
Linda C

Thanks Lindac. If you dont know John Kovac or Mountainside Pottery I sure cant believe what I read on net. Hard to know what sources are correct. Alos, if stacked bowl on bowl would there be stilt marks on bottom also?

Just did a little research.....from what little I find on line, Mountainside's wares were all hand thrown. your bowl sure doesn't look hand thrown....not does the mark look like Mountainside.
And with fine hand made art pottery you would not see stilt marks on the "good side" that was for mass produced stuff that was stacked to conserve kiln space.
Linda C

Just because it has a name does not mean its highly valuable. Yes the mark is right for mp and no it's not a known reproduced company because the pieces don't have enough value to fake. The finish is right and if you look at other mp pieces you will see they often stacked pieces. Not having them on the base does not mean much. Often their pieces were for planters, so the inside was supposed to be filled with dirt but in a basic dough bowl you also are likely to see this. It's quite normal and does not diminish its value.

According to my research, Mountainside Pottery used several different marks. I can find 2 configurations of the letters M and P...in an earlier mark the M and P share a leg....in the other the M has the crossed center lines...but I can find no example of a P with the bottom leg having that horizontal mark.
I also can find nothing indicating that they made the larger sized pieces that might be used as a planter.

There was or perhaps still a Mountainside pottery in North Carolina....but I can't find any pictures of their wares.

I in no way indicated that this piece was "fake" Mountainside pottery but rather that it is real something else.
Linda c