I'm trying to figure out what kind of wood this is. The house was built pre-1900 in central Minnesota. White oak appears to be the main wood in the construction of the house, but when it comes to identifying old forest cut flooring material, I lose. It may be hard to tell by the photo, but the wood is much finer grained than oak but not as much as maple. Its perfectly clear throughout both rooms and has a light brown unfinished appearance. The floor is believed to have likely been sanded in the mid 60's, then covered with vinyl. From what shellac still remains in some low spots, the wood is a warm medium brown. The photo kind of shows black in the wood grain, which may be deceiving. That black is actually some kind of tar material used to glue down asbestos tile in the 1950's. The sanding was done with very course paper, and it left marks in the wood (which are visible as well)