During my research on which states have oil and gold, I came up with codes for the states and provinces that possess them. I think that it would be a shame not to share the list with you so you can find it as a part of our big cheat sheet.
Each state contains different provinces, which are in the game around 40 000+. Because of that number, I created a separate web and listed them there. I definitely recommend checking the specific province IDs in-game.