521.
Mineral leasing claims.
522.
Conflicting periods of location of claims.
524.
Reservation of minerals to United States.
525.
Future location of claims on mineral lands.
526.
Mining and Leasing Act operations.
527.
Determination of unpatented mining claims.
528.
Waiver and relinquishment of mineral rights.
529.
Helium lands subject to entry.
531.
Approval of United States officials.