Kanto Route 3/Manga/Pokémon Adventures

Route 3 appeared in Gyarados Splashes In!. first encountered Misty on this route, fighting a rampaging Gyarados. With the help of Red's Saur, the Gyarados was stopped and eventually caught by Red. Afterwards, Misty told Red that the Gyarados was actually hers, having gone missing some time earlier and returned raging mad.