Get radio card, go to top when near snorlax battle and then you can go to the other areas
After Defeating Misty In Pokemon Soul Silver Ds What Do U Do?
The way you do it is you use your radio on the poke gear, move the signal to the top, for the poke gear, and then you go to snorlax, and he will awaken. Make sure the poke gear is playing on the radio before you talk to Snorlax.you go through radio cave, and to pewter city