Actually, I was going to ask the same question. Artist needs a 1' x 12', but doesn't specify thickness. Unless he is looking for a 1" x 12" x 12', which I'm pretty sure Mill Creek will have. It's tough to get thicker single pieces that wide and that long.
(I had the same sort of issue when I recently built a mantle for my fireplace. I ended up using three pieces of 2"x8"x10' pine from a 100 YO barn, and laminated them to form a 4.5" thick shelf. Looks good, but Artist may not want the stacked look.)
But you have a brain and unlike BreadforBrains, don't always reside in the gutter.
He doesn't even understand the difference between a board and plywood as he proved with his post.