In the United States, laws are in place to allow the private purchase and ownership of land. With this ownership, the inhabitant can develop or exploit the land in any way they see appropriate as long as the activities do not violate the law. The good news is that this also includes the natural resources available beneath the surface of the land.
These freedoms are not common in other areas worldwide. For example, in the United Kingdom, all mineral rights belong to the state, whether or not the natural resources are held on privately-owned land. Since United States citizens are not held to this same standard, they are often in a unique position to sell the rights to those minerals to private corporations for a large up-front payment.