Anyone know where I can find a butcher/meat market/etc that sells marrow bones?
At the Sunset Valley Farmer's Market last weekend, several of the people who sell beef and pork had soup bones of all sort for sale.
WFM usually has them in the case where the frozen meats are. Alternatively, you can ask and they will either cut them for you if they have them, or order them for you. I've done both.