Groundwire or additional grounding electrodes

[Elkchaser]

A friend purchased a property with a hunting cabin that they want to enlarge and live in. Currently has 100 amp main lug panel
fed with two 4/0 AL and one 2/0 AL neutral. No ground wire was pulled in. Fed 95' underground from power co. meter and 200A breaker.
Wanting to upgrade to new 200A Main Breaker panel. What is proper way to ground the system per NEC? Do we need to run a separate ground wire
from the power co. meter and breaker, or can we drive 2 additional ground rods at the cabin and ground the new panel to them. As a follow up, if
we do need to run the ground wire from the power co supply, what size must it be?

 

[Little Bill]

@Elkchaser
What are you retired from? What is your relation to the electrical industry?

 

[tom baker]

You are asking very basic questions any 1st year electrical trainee would know. Send message to Little Bill to clarify this is not a DIY post.