You have to go to a savanna area in the safari zone. Then you have to place down 10 rock items. Then just run around in the grass until you find one.
In Pokémon HeartGold, Rhydon needs to be traded while holding a Protector in order to evolve.
Catch it in the safari zone.
give him a protecter and trade it!! Dur!
Rhydon, if you trade it it will turn into Rhyperior
you cant evolve it on heartgold u can only get it in a sinnoh game
you can find a Rhydon on route 226 :)
You need to evolve Rhydon. Rhydon evolves when you trade it when it holds a Protector. You find a Protector on Iron Island and Route 228. See related link on details on where to find Rhydon.
Never it only evolves in diamond, pearl, platinum, heartgold, soulsilver, black and white.
You can't find rhydon on a map or room so you must get a rhyhorn then train it to level 42 to get rhydon. You can find rhyhorn on certain rooms like FireredAddamsPokemonMansion.
Find a protector, and trade rhyDON, not rhyhorn, while rhyDON is holding it.
you have to trade from another game
you would have to transfer a rhyperior from diamond, pearl, platinum, heartgold or soulsilver. or you could transfer a rhyhorn or rhydon from those games and then evolve it.