Once you defeat Team Rocket in the Goldenrod City Radio Tower and make it through the Ice Path, you are allowed to enter Blackthorn City Gym.
blackthorn city
get on the other side of the ice caves
find the ice path and follow it
In Pokemon sousilver (I don't know about heart gold )you go to blackthorn city which is located in blackthorn city right across the blackthorn city's gym.
Blackthorn City is a location in the game Pokemon Gold. To get there, you have to go through the Ice Path.
on the route between mahogany town and blackthorn city
No it doesn't, it learns it by move tutor in Blackthorn City
You just train your Pokemon heaps.. and its really easy i got on my 1st shot..
she uses dragon type Pokemon and she is the blackthorn city gym on heart gold (UK but available in USA) and Soul silver (USA but available in UK) soul silver and heart gold are both the same except the Pokemon!
blackthorn city, ok, go to your pokegear, it should be on the top-right corner. go to mahogany town, go through ice path, be at blackthorn city! hope it hlpd!
The last gym badge is in viridian city for Kanto. For Johto it is in Blackthorn city.
Have a Pokemon who knows STRENGTH with you, and actually use your smarts to roll all the rocks into a hole.