U.S. Code / Title 30 — Mineral Lands and… / Chapter 15—Surface ResourcesTitle 30SubchapterSubchapter Ii—Mining LocationsContents§ 611. Common varieties of sand, stone, gravel, pumice, pumicite, or cinders, and petrified wood§ 612. Unpatented mining claims§ 613. Procedure for determining title uncertainties§ 614. Waiver of rights§ 615. Limitation of existing rights