Kentucky
From Transformers Wiki
Fiction
The Transformers cartoon
Trypticon stole Fort Knox under Octane's direction, using the vast amount of gold inside to get Abdul Fakkadi, the leader of the small nation of Carbombya (yes, we know), to shelter the duo in his nation longer. They proceeded to steal some other buildings for Fakkadi as well, although the Autobots interfered with the theft of the Kremlin.
Though the Autobot investigation went awry at first, they eventually put two and two together and tracked down Octane and Trypticon. After Metroplex threw his fellow Titan into the ocean again (because it worked so well last time), he returned Fort Knox, as well as the Taj Mahal, to its rightful position. Thief in the Night
2005 IDW continuity
As part of his efforts to welcome Earth into the Council of Worlds, Optimus Prime oversaw the opening of an bi-species Ore-13 mine in Kentucky for both human and Cybertronian employees. Surfeit of Primes