Purchase prime rib with a layer of fat on it to keep it moist and tender when cooking it Traeger-style. The fat forms a crust when cooking. The butcher should cut a portion of the fat to expose the end of the bones. Coat the roast with a prime rib rub, wrap it in plastic and place it in the refrigerator for 24 hours before grilling.
Start the grill on smoke with an open lid for about five minutes or until flames are established. Turn the temperature setting to 375 degrees Fahrenheit for 15 minutes in order to pre-heat. Place the prime rib on the grill fat side up, and lower the temperature to 300 degrees Fahrenheit, or medium setting. Close the lid, and cook the meat for three to four hours until done. The internal temperature for rare meat should be 130 degrees. Medium cooked meat should have an internal temperature of 145 degrees and well-done meat, 160 degrees. Remove the meat from the grill, and let it rest in the foil for 15 minutes before carving and serving.
Traeger is a maker of wood pellet grills and accessories. TraegerGrills.com offers grills, pellets, sauces and rubs for both home and commercial use.