That all lands granted by this act shall be disposed of only at public sale after advertising - tillable lands capable of producing agricultural crops for not less than $10 per acre and lands principally valuable for grazing purposes for not less than $5 per acre. Any of the said lands may be exchanged for other lands, public or private, or equal value and as near as may be of equal area, but if any of the said lands are exchanged with the United States such exchange shall be limited to Federal lands that are surveyed, nonmineral, unreserved public lands within the state or are reserved public lands within the State that are subject to exchange under the laws governing the administration of such Federal reserved public lands. All exchanges heretofore made under section 11 of the Act approved February 22, 1889 (25 Stat. 676), as amended by the Act approved May 7, 1932 (47 Stat. 150), for reserved public lands of the United States that were subject to exchange under law pursuant to which they were being administered and the requirements thereof have been met, are hereby approved to the same extent as though the lands exchanged were unreserved public lands. The said lands may be leased under such regulations as the legislature may prescribe. The state may also, upon such terms as it may prescribe, grant such easements or rights in any of the lands granted by this act, as may be acquired in privately owned lands through proceedings in eminent domain: provided, however, that none of such lands, nor any estate or interest therein, shall ever be disposed of except in pursuance of general laws providing for such disposition, nor unless the full market value of the estate or interest disposed of, to be ascertained in such manner as may be provided by law, has been paid or safely secured to the state. With the exception of the lands granted for public buildings, the proceeds from the sale and other permanent disposition of any of the said lands and from every part thereof, shall constitute permanent funds for the support and maintenance of the public schools and the various state institutions for which the lands have been granted. Rentals on leased land, proceeds from the sale of timber and other crops, interest on deferred payments on land sold, interest on funds arising from these lands, and all other actual income, shall be available for the acquisition and construction of facilities, including the retirement of bonds authorized by law for such purposes, and for the maintenance and support of such schools and institutions. Any state may, however, in its discretion, add a portion of the annual income to the permanent funds. Notwithstanding the foregoing provisions of this section, each of the states of North Dakota, South Dakota, and Washington may pool the moneys received by it from oil and gas and other mineral leasing of said lands. The moneys so pooled shall be apportioned among the public schools and the various state institutions shall receive an amount which bears the same ratio to the total amount apportioned as the number of acres (including any that may have been disposed of) granted for such public schools or for such institutions bears to the total number of acres (including any that may have been disposed of) granted by this act. Not less than fifty per centum of each such amount shall be covered into the appropriate permanent fund. The lands hereby granted shall not be subject to pre-emption, homestead entry, or any other entry under the land laws of the United States whether surveyed or unsurveyed, but shall be reserved for the purposes for which they have been granted. History: As amended by Act of August 11, 1921, ch. 61, 42 Stat. 158; Act of May 7, 1932, ch. 172, 47 Stat. 150; Act of June 25, 1938, ch. 700, 52 Stat. 1198; Act of April 13, 1948, ch. 183, 62 Stat. 170; Act of June 28, 1952, ch. 480, 66 Stat. 283; Act of June 30, 1967, Public Law 90-41, 81 Stat. 106; Act of October 16, 1970, Public Law 91-463, 84 Stat. 987. Condemnation of School Lands. Where a state statute relating to the condemnation of right of way by the state highway commission contemplates that title to lands shall be acquired, such procedure cannot be resorted to acquire school land granted to the state. State Hwy. Comm'n v. State, 70 N. D. 673, Oil and Gas Leases Under the Enabling Act, as amended, the state has full power to provide for the execution of oil and gas leases on school and university lands. State ex rel. Rausch v. Amerada Petro. Corp., 78 N.D. 247, 49 N.W.2d 14 (1951). Taxation When a contract for the sale of school land is canceled, the land reverts to the state, and no interest in the land is subject to taxation until a resale or redemption is made. Upon reversion of the land to the state, all unpaid taxes levied thereon are canceled. State v. Towner County,