My guess is surface Excavation rights are probably not same as Surface rights. At least not to the same extent.
Basicly they own the gravel but not necessarily the surface much along a mineral claim would give one except that the matter of interest is at or close to the surface.

If I have some gravel on my property or even a valuable mineral, is it actually mine?
Or if I have a farm field under which there might be oil, does an oil company have equal surface rights on that property to mine? I think I have priority and must be compensated IF trespassed upon.

Again, I am most interested how the legal system looks on all this.