SOS Encounter: Mount Hokulani
Walk: Mount Hokulani (20%)
Its base catch rate is 3 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Great Ball, Net Ball or Heavy Ball.
Evolution: Beldum → Metang (Level 20) → Metagross (Level 45).
Beldum in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)