The prime rib roast comes from the back of the upper rib section of the steer. It includes a total of 12 ribs where the best part is 6-12. The ribs further away from the shoulder are considered the first cut and are most prized because they are more tender. The bone in rib roast is what we all know as the standing rib roast. When you remove the bones, you have the coveted prime rib roast. When you slice it into steaks, you have the ribeye steak.