Only in Ultra Sun & Ultra Moon
SOS Encounter: Paniola Ranch
Walk: Paniola Ranch (30%)
Its base catch rate is 235 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 Quick Ball or Ultra Ball.
Evolution: Mareep → Flaaffy (Level 15) → Ampharos (Level 30).
Mareep in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)