Remove arm roast from packaging, rinse with cold water, and pat dry with paper towels.
Season generously with salt, freshly cracked black pepper and garlic powder.
Place arm roast directly on the smoker grate and insert your smoker’s thermometer probe. Smoke for 3-4 hours until the meat reaches an internal temperature of 130° F.
Place arm roast in an aluminum pan with beef broth. Reinsert the thermometer and cover tightly with aluminum foil.
Increase temperature to 250° F and smoke for another 4-5 hours until the meat reaches an internal temperature of 203° F.
Remove from smoker and let rest for 30 minutes.
Slice beef against the grain, or shred* and serve warm with pan juices.
Notes
*I typically will shred the super tender parts of the roast and then slice the part that's not quite falling apart to mimic a brisket.