I was looking up how to get the rods in heart gold, and I got that good rod was in olivine city. I knew that, but it said that the super rod was on route 12 in Kanto. Im pretty sure it is, but I also remember seeing it somewhere else. Cant you get it in the lake of rage? Thats where I always got it.
Nope, you cannot get the Super Rod anywhere else other than Route 12 in Kanto in HeartGold.
Hope I helped!