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1–18 Act of August 11, 1955 (30 U.S.C. Chapter 16): All lands previously withdrawn for power sites, except those actually in use or being constructed upon, were restored to mining locations subject to future use for power development under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.
1–21 Act of December 24, 1970 (30 U.S.C. Chapter 23): This act provides for geothermal steam leases and should the lease be terminated, the lessee has the right to complete the location of mining claims for minerals subject to location which would constitute a byproduct if commercial production of steam continued. Conversion to a lease under the Mineral Leasing Act for lease minerals is provided for if the lease minerals are capable of being produced in commercial quantities.
1–22 Act of October 21, 1976 (43 U.S.C. 1744; 43 C.F.R. 3833): All unpatented mining claims, including lodes, placers, mill sites and tunnel sites located prior to this date must be recorded with the proper state office of the Bureau of Land Management by filing a copy of the record of the location (or last amended) notice or certificate, as required by state law, together with a map showing the claim and its relation to the public land survey or protracted grid, by October 21, 1979; and also provide evidence of assessment work for the preceding assessment year, or notice of intention to hold, and thereafter prior to December 31 of each calendar year. Claims located after October 21, 1976 shall be recorded within 90 days of date of location and evidence of assessment work or notice of intention to hold, if assessment work is not required, filed prior to December 31 of each calendar year after the year of location. Change in ownership must also be recorded and (presumably) amended location certificates. If these recording requirements are not met, the claims are deemed to be abandoned.