You will need picks, dynamite, and TNT to work in the mine. There are several ways to get them:
1. Send out trains loaded with goods. They often bring back mining tools along with the usual construction materials.
2. Find mining tools in the mine itself. They may be hidden in earth tiles or bottles with messages.
3. Make sure to visit the market. It has special deals on mining tools every once in a while.
4. Play at the House of Luck to win mining tools as prizes.
5. Open treasure chests. They can be found in the mine or your friends' towns, brought by ships from the islands, and given as a reward for sending fully loaded airplanes.
6. Ask your co-op members for mining tools using the co-op chat.
7. Take part in weekly regattas. You can get mining tools as rewards for strong finishes.
8. Use Township Cash to buy any mining tools you need right from the mine.