If dry brining the meat, apply up to 3 tablespoons of Kosher salt the night before you plan to cook it
Bring your Prime Rib to room temperature, then preheat the smoker. Apply the seasoning mix without adding salt if you dry brine the meat, otherwise use 1 tablespoon of Kosher salt in it. Rub the seasoning into the meat, adding extra to the fat cap
Place the Prime Rib in the smoker and watch the temperature to make sure it maintains at 225 to 250 degrees F for the entirety of the cooking time
Begin checking the internal temperature of the meat at around 1.5 to 2 hours. When the internal temperature reaches 130 to 135 degrees F, switch the smoker to a high temperature for 10 minutes to sear the surface. You can also finish this step in your oven or on a large cast iron pan
Let the Prime Rib rest for at least 20 to 30 minutes, covered by a tent of aluminum foil to keep moisture in. Then carve and serve immediately