No person, firm, or corporation shall hold under lease at any one time without special permission from the Secretary of the Interior in excess of the following areas:
- (a) For deposits of the nature of lodes, or veins containing ores of gold, silver, copper, or other useful metals, 640 acres.
- (b) For beds of placer gold, gypsum, asphaltum, phosphate, iron ores, and other useful minerals, other than coal, lead, and zinc, 960 acres.
- (c) For coal, 4,800 acres.
- (d) For lead and zinc, 1,280 acres.