Walnut and maple., it's an inch and a quarter thick, 12 1/2 inches wide and about 17 inches long. While it is an end grain cutting board I actually built it with kneading dough in mind, I don't intend to cut on this one, not for awhile anyway. Built it this weekend and baked some bread with it today. Which is why my mixer is covered in flour. I'm really happy with this one.
Sanding isn't that bad, I put on a noise cancelling headset with some tunes on and then I can just vibe out while the random orbital does the work. It's kind of a nice change of pace from the constant thinking about dimensions and processes. Sanding a cutting board can become an hour of guaranteed peace.
sounds like you found the zen of it!