On and after March 15, 1940, mining locations made under the mining laws of the United States upon lands within four hundred feet of the center line of the Catalina Highway, Coronado National Forest, Arizona, which highway begins at the south boundary of said national forest near the southeast corner of section 7, township 13 south, range 16 east, Gila and Salt River base and meridian, and runs in a general northerly direction for a distance of about twenty-five miles to Soldier Camp, shall confer on the locator no right to the surface of the land described in his location other than the right to occupy and use, under the rules and regulations relating to the administration of the Coronado National Forest, so much thereof as may be reasonably necessary to carry on prospecting and mining, and shall not authorize the taking of any resource other than the mineral deposits, or the occupancy of said land for any purpose other than prospecting and mining; and each patent issued thereafter under the United States mining laws upon a mineral location made upon lands within four hundred feet of said center line shall convey title only to the mineral deposits within said land and the right, subject to rules and regulations relating to the national forests, to occupy and use the surface of the land for prospecting and mining only: Provided, That valid mining claims within said lands existing on March 15, 1940, and thereafter maintained in compliance with the laws under which they were initiated and the laws of the State of Arizona may be perfected in accordance with the laws under which they were initiated.