Season heavily on all sides with Montana Outlaw BBQ Beef Rub, coarse ground salt and pepper. Let it rest in the fridge between 2 hours to overnight.
Using Royal Oak Charcoal and Tumbleweeds, light the tumbleweeds to get hte charcoal going. Add wood when charcoal is hot. Heat smoker to 275-300 degrees.
Remove prime rib from the fridge a 1/2 hour before cook so it may rise to room temperature.
Smoke at 300 degrees for 2-4 hours (depending on size).
Baste with butter and rosemary throughout the cook to keep it moist.
Cover with foil and let rest half 1/2 hour before serving.