They are unlocked at experience level 34.
They are stored in the barn.
A sure way to get a pickaxe is to buy it with 12 dia or to hire Tom and have him find some.
Pickaxes can also sometimes be found in roadside shops for 1 to 126 coin per pickaxe.
Finally, pickaxes can be randomly obtained when players:
- harvest crops
- collect products or animal goods
- cut down trees and bushes
- feed pets
- open mystery boxes and mystery packages
- spin the Wheel of Fortune
- participate in global events
- fully satisfy a town visitor
- win prizes in derbies
- use mystery nets in the fishing lake
- watch a Night at the Movies trailer