=1–13= Act of April 28, 1904 (30 U.S.C. 34): The monuments on the ground shall constitute the highest authority as to which lands are patented notwithstanding a conflict with the survey record or the calls and descriptions recited in the patent. Also, in extending the public land surveys, all patented mineral claims shall be segregated from the public lands as they are monumented on the ground. =1–14= Act of February 25, 1920 (30 U.S.C. Chapter 3A): The Mineral Leasing Act removed deposits of oil, gas, coal, potassium, sodium, phosphate, oil shale, native asphalt, solid and semi-solid bitumen and bituminous rock, including oil impregnated rock or sands, and sulphur in Louisiana and New Mexico from the general mining laws and other laws and set up a system of leasing for these minerals. =1–15= Act of July 31, 1947 (61 Stat. 681): The Materials Act authorized the sale of mineral materials if the disposal of such materials was not otherwise expressly authorized by law. =1–16= Act of August 13, 1954 (30 U.S.C. 521): Provided for multiple development of mineral deposits under the mining and mineral leasing laws. All mining claims and mill sites located after this date, and those prior to this date that did not preserve their rights, do not include leasable minerals, such minerals being subject to exploration and development under the Mineral Leasing Act. =1–17= Act of July 23, 1955 (30 U.S.C. 601): Removed common varieties of sand, stone, gravel, pumice (except block pumice), pumicite or cinders from appropriation under the general mining laws. Also restricted the use of the surface of unpatented mining claims to that portion necessary for the development and mining of the deposit and permitted the federal government to manage the surface and vegetative resources. =1–18= Act of August 11, 1955 (30 U.S.C. Chapter 16): All lands previously withdrawn for power sites, except those actually in use or being constructed upon, were restored to mining locations subject to future use for power development under the authority of the United States, without reimbursement, and subject to provisions for recording the location within 60 days from date of location and assessment work within 60 days of the expiration of the assessment year. =1–19= Act of March 18, 1960 (30 U.S.C. 42): Provided for the location of mill sites in conjunction with placer claims subject to the same requirements of survey as placers. This allowed location of mill sites by legal subdivisions. =1–20= Act of September 28, 1962 (76 Stat. 652): Provides for free use of petrified wood.