Route 17 (quest), Route 14, 15, 17, Celadon City, Celadon Sewers, Pokemon Mansion, Power Plant
Route 17 (quest), Route 14, 15, 17, Celadon City, Celadon Sewers, Pokemon Mansion, Evolve Grimer (Lv38)
Route 5 (trade), Route 2, 4, 7, 10, 12, 13, 14, 15, 17, 19, 20, 21, 22, 23, 24, 30, 31, 35, 43, 44, Blackthorn City, Cerulean Cape, Cerulean Cave, Cerulean City, Cinnabar Island, Crimson City, Ilex Forest, Mt. Silver Base, Pallet Town, Ruins of Alph, Safari Zone A1, A2, A3, A4, A5, Treasure Beach, Vermillion City, Violet City, Viridian River
Route 6, 8, 14, 15, 22, 23, 24, 30, 31, 35, 43, 44, Blackthorn City, Cerulean Cape, Cherrygrove City, Crimson City, Ilex Forest, Mt. Silver Base, Pallet Town, Safari Zone A1, A2, A3, A4, Violet City, Evolve Poliwag (Lv25)
Route 30, 31, 35, 43, Cherrygrove City, Ilex Forest, Mt. Silver Base, Violet City, Evolve Poliwhirl (Water Stone)
Route 30, 31, 35, 43, Ilex Forest, Mt. Silver Base, Violet City, Evolve Poliwhirl (Lv37 or King's Rock)