This section and section 141 1

Entries existing on February 7, 1925, and allowed prior to April 1, 1924, under the Stock Raising Homestead Act of December 29, 1916 (Thirty-ninth Statutes at Large, page 862) [43 U.S.C. 291 et seq.], for land withdrawn as valuable for oil or gas, but not otherwise reserved or withdrawn, are validated, if otherwise regular: Provided, That at date of entry the land was not within the limits of the geologic structure of a producing oil or gas field.

Whenever in the opinion of the Secretary of the Interior any lands which have been withdrawn under the provisions of sections 141 1

Upon payment of the purchase price the Secretary of the Interior is authorized by appropriate patent to convey all the right, title, and interest in and to said lands to the purchaser at said sale, subject, however, to such reservations, limitations, or conditions as said Secretary may deem proper: Provided, That not over one hundred and sixty acres shall be sold to any one person: Provided further, That any patent issued hereunder shall contain a reservation to the United States of all oil, gas, coal, and other mineral.

The moneys derived from the sale of such lands and improvements shall be disposed of as are other receipts from the sale and disposal of public lands.

Any private land over which an Indian reservation has been extended by Executive order, may be exchanged at the discretion of the Secretary of the Interior and at the expense of the owner thereof and under such rules and regulations as may be prescribed by the Secretary of the Interior, for vacant, nonmineral, nontimbered, surveyed public lands of equal area and value and situated in the same State or Territory.

No public lands of the United States shall be withdrawn by Executive Order, proclamation, or otherwise, for or as an Indian reservation except by act of Congress.

When public lands are excluded from national forests or released from withdrawals the President may, whenever in his judgment it is proper or necessary, provide for the opening of the lands by settlement in advance of entry, by drawing, or by such other method as he may deem advisable in the interest of equal opportunity and good administration, and in doing so may provide that lands so opened shall be subject only to homestead entry by actual settlers only or to entry under the desert-land laws for a period not exceeding ninety days, the unentered lands to be thereafter subject to disposition under the public-land laws applicable thereto.

Where under the law the Secretary of the Interior is authorized or directed to make restoration of lands previously withdrawn he may also restrict the restoration as prescribed in section 151 of this title.

Upon receipt of a proper deed from the State of North Dakota, executed under authority of the act of its legislative assembly, approved February 5, 1915, reconveying to the United States title to section 16, township 138 north, range 81 west, fifth principal meridian, the Secretary of the Interior is authorized to issue patents to said State for such vacant, surveyed, unreserved, unoccupied, nonmineral public lands as may be selected by said State within its boundaries, not exceeding one thousand two hundred and eighty acres in aggregate area, and said section when so reconveyed shall not be subject to settlement, location, entry, or selection under the public land laws, but shall be reserved for the use of the Department of Agriculture in carrying on experiments in dry-land agriculture at the Northern Great Plains Field Station, Mandan, North Dakota.

Where public lands of the United States have been withdrawn for possible use for construction purposes under the Federal reclamation laws, and are known or believed to be valuable for minerals and would, if not so withdrawn, be subject to location and patent under the general mining laws, the Secretary of the Interior, when in his opinion the rights of the United States will not be prejudiced thereby, may, in his discretion, open the land to location, entry, and patent under the general mining laws, reserving such ways, rights, and easements over or to such lands as may be prescribed by him and as may be deemed necessary or appropriate, including the right to take and remove from such lands construction materials for use in the construction of irrigation works, and/or the said Secretary may require the execution of a contract by the intending locator or entryman as a condition precedent to the vesting of any rights in him, when in the opinion of the Secretary same may be necessary for the protection of the irrigation interests. Such reservations or contract rights may be in favor of the United States or irrigation concerns cooperating or contracting with the United States and operating in the vicinity of such lands. The Secretary may prescribe the form of such contract which shall be executed and acknowledged and recorded in the county records and United States local land office by any locator or entryman of such land before any rights in their favor attach thereto, and the locator or entryman executing such contract shall undertake such indemnifying covenants and shall grant such rights over such lands as in the opinion of the Secretary may be necessary for the protection of Federal or private irrigation in the vicinity. Notice of such reservation or of the necessity of executing such prescribed contract shall be filed in the Bureau of Land Management and in the appropriate local land office, and notations thereof shall be made upon the appropriate tract books, and any location or entry thereafter made upon or for such lands, and any patent therefor shall be subject to the terms of such contract and/or to such reserved ways, rights, or easements and such entry or patent shall contain a reference thereto.

The Secretary of the Interior may prescribe such rules and regulations as may be necessary to enable him to enforce the provisions of this section.

No public land, water, or land and water area shall, except by Act of Congress, on and after February 28, 1958 be (1) withdrawn from settlement, location, sale, or entry for the use of the Department of Defense for defense purposes; (2) reserved for such use; or (3) restricted from operation of the mineral leasing provisions of the Outer Continental Shelf Lands Act [43 U.S.C. 1331 et seq.], if such withdrawal, reservation, or restriction would result in the withdrawal, reservation, or restriction of more than five thousand acres in the aggregate for any one defense project or facility of the Department of Defense since February 28, 1958, or since the last previous Act of Congress which withdrew, reserved, or restricted public land, water, or land and water area for that project or facility, whichever is later.

All withdrawals or reservations of public lands for the use of any agency of the Department of Defense, except lands withdrawn or reserved specifically as naval petroleum, naval oil shale, or naval coal reserves, heretofore or hereafter made by the United States, shall be deemed to be subject to the condition that all minerals, including oil and gas, in the lands so withdrawn or reserved are under the jurisdiction of the Secretary of the Interior and there shall be no disposition of, or exploration for, any minerals in such lands except under the applicable public land mining and mineral leasing laws: Provided, That no disposition of, or exploration for, any minerals in such lands shall be made where the Secretary of Defense, after consultation with the Secretary of the Interior, determines that such disposition or exploration is inconsistent with the military use of the lands so withdrawn or reserved.