They shall be bodies corporate and politic under the respective names designated in the decrees by which they were incorporated, and shall have and possess the following powers:
Provided, however, that no sale of the lands held in common can be made to persons who are nonheirs of the grant unless a majority of such heirs present at a mass meeting to be called fifteen (15) days in advance thereof by the president of the board of trustees vote in favor of any proposed sale to nonheirs, and provided, further, that no lease of the lands held in common can be made to any person whatsoever for a period of time exceeding twenty (20) years; provided, further, nevertheless, that as to any oil and gas lease executed upon lands held in common where oil and gas or either of them in commercial quantities is being, or shall be, produced from lands covered by said lease, then and in such event, this limitation as to the period of time shall not apply as to any such oil and gas lease so long as oil or gas or either of them is being produced in commercial quantities from said land;
NMS § 49-2-2