You go to Blackthorn City by taking the Ice Path I think.
beat the 6th gym leader and then go to mahogany town.
Mahogany town, just south of lake of rage.
Blackthorn City, after Mahogany Town and after Ice Path
Beat Jasmine in Olivine. Done that then go to Mahogany.
It is in Mahogany town in the southwestern corner of the town.
The Red Scale is a scale that you obtain after defeating/capturing the Red Gyrados in the Lake of Rage in Mahogany Town.
blackhorn city i think its next to mahogany town
fail...
Mahogany Town
Mahogany Town
Mahogany Town.
Mahogany Town.