North Dakota Constitution Art. IX, § 5

After one year from the assembling of the first legislative assembly the lands granted to the state from the United States for the support of the common schools, may be sold upon the following conditions and no other: No more than one-fourth of all such lands shall be sold within the first five years after the same become salable by virtue of this section. No more than one-half of the remainder within ten years after the same become salable as aforesaid. The residue may be sold at any time after the expiration of said ten years. The legislative assembly shall provide for the sale of all school lands subject to the provisions of this article. In all sales of lands subject to the provisions of this article all minerals therein, including but not limited to oil, gas, coal, cement materials, sodium sulphate, sand and gravel, road material, building stone, chemical substances, metallic ores, uranium ores, or colloidal or other clays, shall be reserved and excepted to the state of North Dakota, except that leases may be executed for the extraction and sale of such materials in such manner and upon such terms as the legislative assembly may provide.