ORS § 541.230
No lands belonging to the state, within the areas to be irrigated from work constructed or controlled by the United States or its authorized agents, shall be sold except in conformity with the classification of farm units by the United States. The title of such land shall not pass from the state until the applicant therefor has fully complied with the provisions of the laws of the United States and the regulations thereunder concerning the acquisition of the right to use water from such works, and shall produce the evidence thereof duly issued. After the withdrawal of lands by the United States for any irrigation project, no application for the purchase of state lands within the limits of such withdrawal shall be accepted, except under the conditions prescribed in this section. Any state lands needed by the United States for irrigation works may, in the discretion of the Department of State Lands, be conveyed to it without charge.
ORS 541.230