You can notify officials if you'd like, but I don't believe there is any law about that having to be done. If you own the property you should have every right to it.
You are not required to notify anyone if you find gold. You may and may not have mineral rights on your property, if so, the gold is yours. If you do not have mineral rights, you may not collect or sell the gold.
if i were you ....Never .... i would be THE HAPPIEST THING ON THE ENTIRE WORLD :))) the officials should stay away from my property :)) it's my gold i found it