The commissioner of public lands of the state of Washington is authorized to cooperate with the secretary of the interior of the United States with a view to facilitate the execution of plans approved by the secretary of the interior for subdivision and disposal of lands under federal reclamation projects constructed or to be constructed under the provisions of the act of congress of June 17, 1902, (32 Stat., 388) and acts amendatory thereof or supplementary thereto in farm units bounded by lines considered more economical and convenient for irrigation and reclamation than the lines of legal subdivisions and for such purpose is authorized to cause to be prepared and filed a plat or plats of any state lands in any such federal reclamation project showing said state lands subdivided into blocks, lots or farm units, with boundary lines other than those of legal subdivisions, and located with a view to greater convenience, economy or efficiency in irrigation and reclamation, and such subdivision into lots, blocks or farm units may be made in harmony with any general plan approved by the secretary of the interior for subdivision of the lands of any such federal reclamation project or any part or division of any such project into blocks, lots or farm units with boundary lines other than the boundary lines of legal subdivisions and designed for more convenient, economical or efficient reclamation and irrigation. And the commissioner of public lands is authorized to offer for sale and to sell such state lands, in the lots, blocks or farm units designated on such plat or plats instead of offering and selling the same in the legal subdivisions of the U.S. public land surveys.