Cast Iron Cavern:
Magnemite
Nosepass (will evo into steel)
Pawniard
Smeltix (custom steelix thats steel/fire)
Molten Steel Pit:
Aron
Cold Steel Cavern:
Drilbur (will evo into steel)
Mawile
Badlands:
Pawniard
The Cavern of Knowledge:
Aron
Honedge
Beldum
theres a pokemon by routes list on page 9