CALL BEFORE YOU DIG.
We called Advanced Underground originally because we wanted to know if we could dig some footings for a deck and the utility company will only mark from the street to the house.
Kali from Advanced Underground came out the next afternoon and found electrical, gas, and water lines we didn't even know we had.
Kali was responsive, punctual, professional, and explained in detail what he had found, and what it meant. We have a pool, and old lighting throughout our yard, so he had his work cut out for him. He also answered all of our questions, and marked some additional electrical in the front yard we had forgotten to mention when we originally called.
If we need to dig again, Advanced Underground Utility Locating is going to be our first call.