30 U.S.C. §§ 28b–28e

The performance of not less than $100 worth of labor or the making of improvements aggregating such amount, which labor or improvements are required under the provisions of section 28 of this title to be made during each year, may be deferred by the Secretary of the Interior as to any mining claim or group of claims in the United States upon the submission by the claimant of evidence satisfactory to the Secretary that such mining claim or group of claims is surrounded by lands over which a right-of-way for the performance of such assessment work has been denied or is in litigation or is in the process of acquisition under State law or that other legal impediments exist which affect the right of the claimant to enter upon the surface of such claim or group of claims or to gain access to the boundaries thereof.

The period for which said deferment may be granted shall end when the conditions justifying deferment have been removed: Provided, That the initial period shall not exceed one year but may be renewed for a further period of one year if justifiable conditions exist: Provided further, That the relief available under sections 28b to 28e of this title is in addition to any relief available under any other Act of Congress with respect to mining claims.

All deferred assessment work shall be performed not later than the end of the assessment year next subsequent to the removal or cessation of the causes for deferment or the expiration of any deferments granted under sections 28b to 28e of this title and shall be in addition to the annual assessment work required by law in such year.

Claimant shall file or record or cause to be filed or recorded in the office where the notice or certificate of location of such claim or group of claims is filed or recorded, a notice to the public of claimant’s petition to the Secretary of the Interior for deferment under sections 28b to 28e of this title, and of the order or decision disposing of such petition.