You don't 'get past' stark mountain. There is no further to go on the map.
However there is a little storyline in there with buck, team galactic and the inspector dude.
To complete this you'll need pokemon with strength, rock smash and rock climb.
Run around the area and find your way to the top left area, buck will disappear and for going into the cave you will have to fight Jupiter and Mars, if you beat them then woo.
After you finish talking outside go to the survival area where you'll find buck, inside the building are all the gym leaders and you can constantly battle them.
After you talk to buck in there you can go back to stark mountain and catch the legendary Heatran. Hurrah!
However there is a little storyline in there with buck, team galactic and the inspector dude.
To complete this you'll need pokemon with strength, rock smash and rock climb.
Run around the area and find your way to the top left area, buck will disappear and for going into the cave you will have to fight Jupiter and Mars, if you beat them then woo.
After you finish talking outside go to the survival area where you'll find buck, inside the building are all the gym leaders and you can constantly battle them.
After you talk to buck in there you can go back to stark mountain and catch the legendary Heatran. Hurrah!
