Preheat oven to 450°F.
Place the bones and the vegetables in a large roasting pan and roast for 40 minutes, or until the bones have thoroughly browned. Periodically turn them over, and baste the bones and vegetables with any accumulated fat drippings. Pour the bones and vegetables into a very large stockpot.
Set the roasting pan on the stovetop, and pour in 2 cups of the water. Over medium heat, bring the water to a simmer, scraping up the browned bits, and add to the stockpot with any drippings. Tie the thyme and oregano springs together, making a bouquet, and add them to the pot along with the garlic, tomato, salt, and remaining 6 1/2 quarts of water, and vinegar. Allow the mixture to rest for 30 minutes.
Bring the moisture to a boil, skimming off any scum that rises to the surface. Reduce the heat to low, and slowly simmer the stock for a minimum of 6 hours. The longer you cook your stock down, the richer it will be. I often simmer stock all day, store it in the refrigerator for the night, and then continue simmering it for several hours the next morning.
Remove all the bones, vegetables, and herbs. Completely cool the stock before pouring it into freezer containers. If you wish, skim off any fat that has risen to the surface before you pack it away.
Source: Hayes, Shannon. "Beef Stock." The Grassfed Gourmet Cookbook: Healthy Cooking and Good Living with Pasture-Raised Foods. New Jersey: Eating Fresh Publications, 2004. 78-79. Print.