Yup. There are plenty of dormant mines here in Colorado because "there is 100 million dollars worth of gold in that mine but it will cost 200 million dollars to extract it". Once the first number changes enough in relation to the second, those mines will start right back up.
A high profile example is the Donlin project in Alaska. They've been spending decades on de-risking and logistics, and once the gold becomes valuable enough to extract it's likely to be one of the largest mines in the world.
