Have been asking lumber yards and other places about Baltic Birch ply
availability getting mostly half blank stares as if they hadn't heard
of it before. Recently went to plywood section of local Lowes and
there was a single slab of 1/2" X 5' X 5'. Asked where the rest was
being stored and wood section Mgr said that piece was special order
and walked away with it under his arm. There was a stack of 3/4" X 4'
X 8' labeled Birch ply that had characteristic thin plies making up
the total 23/32" thickness that the Mgr identified as BB. Also some
1/4" X 4' X 8'slabs were there and he said that was all they carried.

Search of their site discloses "Not available at that store". I sent
mail asking how it not available but it was there from special order.
So far that is still open. Suggested in the mail they work up a query
option by product name or category listing what items CAN be special
ordered. They answered the mail stating it would be forwarded to
appropriate people and they called at 7PM to say the same thing.