After you beat the gym leader before Clair that guy that was blocking your way before will let you through.
blackthorn city
blackthorn city
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.
In Blackthorn City.
in heart gold u have to go to the route under Blackthorn city
Blackthorn city
A guy gives it to you when you are trying to get to blackthorn city.
Yes. He is in Blackthorn City
You can catch dragonair in the dragons den (blackthorn city).
find the ice path and follow it
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!
Clair is in Blackthorn City, you can battle her straightaway