A bill to amend section 21 of the Act of February 25, 1920, commonly known as the Mineral Leasing Act.

Amends the Mineral Lands Leasing Act to authorize holders of leases of oil shale lands to lease additional lands for purposes connected with operations pursuant to an oil shale lease.

Limits such additional leases to not more than 6,400 acres. Provides that land leased pursuant to this Act may not be used for oil shale mining but may be used for any other purpose authorized by the Secretary of the Interior.

Requires the lessee to show to the Secretary's satisfaction that the lessee needs the additional land and has the ability to conduct environmentally safe operations. Requires the Secretary's determination that the additional lease is in the public interest. Establishes guidelines for other lease provisions including rent and duration.