Level 55
magikarp dratini dragonair
No, you need to evolve a Dragonair.
You must evolve Dragonair, which you get in the Dragon's Den.
Dragon's Den (Blackhorn City)
You level up a Dragonair to Level55 then - hopefully - it will evolve into a Dragonite.
Dragonair are found rarely at Mt. Coronet.
You must evolve Dragonair (available from the Dragon's Den; use super rod) to get it.
in map 4
Mount silver, or the elite four (With exp share.)
Dratini evolves into Dragonair at level 30.
First you have to play the casino/games place in goldenrod city (where you battle whitney) and earn game points by playing voltorb. Once you get enough points you can redeem them for a dragonair. Hope it helps. P.S. the games place is not inside the gym.