The Secretary of the Interior is authorized to purchase or rent not to exceed twenty thousand acres of land or interests therein in suitable locations in the State of California, for the management and control of migratory waterfowl and other wildlife in connection therewith, from moneys to be appropriated by Congress from time to time: , That no sums appropriated under this authority for the acquisition of lands shall be expended for such purpose unless and until the State of California shall have set aside and made available for expenditure funds for the purchase of equivalent acreages as determined by the Secretary of the Interior.Provided