>>50497513The Dratini Line is native to both Kanto and Johto.
In fact, the secretive nature of the Dragon Tamer Clan meant that everyone thought Dratini and its evolutions were outright legends, but the Zukan tells us that in the Gameboy Era of Pokemon's lore, it wasn't until the Safari Zone got commercialized and went public that a fisher was lucky enough to reel a Dratini out of its waters; A discovery so astonishing to everyone everywhere that it points towards the dragon species being native rather than a luxury import.
It was this discovery that basically resulted in the mystique surrounding Dragon Type Pokemon to mostly fade, and as such the Dragon Tamer Clan no longer had a reason to hide them from the world, which is where trainers like Lance and Clair come into position as League Officials, whether at the highest order or as a Gym Leader.