For the purpose of preserving and consolidating certain timber stands along the western boundary of the Yosemite National Park, the President of the United States is authorized, upon the joint recommendation of the Secretaries of the Interior and of Agriculture, to add to said park by Executive proclamation any or all of the following-described lands: Sections 19, 20, 29, 30, 31, and 32, township 1 south, range 20 east, Mount Diablo meridian; east half section 1; east half section 12; southeast quarter section 24, township 2 south, range 19 east, Mount Diablo meridian; sections 4, 5, and 6; north half section 7; sections 8 and 9, and 19 and 20, township 2 south, range 20 east, Mount Diablo meridian, approximately nine thousand acres.