The National Historic Preservation Program provides for the protection of sites, landmarks, and the nation's heritage pursuant to the National Historic Preservation Act of 1966, as amended.
According to 16 U.S.C. 470f:
The head of any Federal agency having direct or indirect jurisdiction over a proposed Federal or federally assisted undertaking in any State and the head of any Federal department or independent agency having authority to license any undertaking shall, prior to the approval of the expenditure of any Federal funds on the undertaking or prior to the issuance of any license, as the case may be, take into account the effect of the undertaking on any district, site, building, structure, or object that is included in or eligible for inclusion in the National Register. The head of any such Federal agency shall afford the Advisory Council on Historic Preservation established under Title II of this Act a reasonable opportunity to comment with regard to such undertaking.
This meant that the Forest Service had to "take into account" the effect that building the G-O Road might have on an area that could be eligible for inclusion in the National Register. The process of determining whether the area is eligible is expressed in 36 CFR 800.
Following these procedures, Six Rivers Forest Supervisor Joseph H. Harn submitted a request on April 4, 1980, to make the area within the Helkau District eligible for the National Register. California State Historic Preservation Officer Knox Mellon reviewed the request favorably, the Secretary of the Interior endorsed it, and on May 21, 1981, the Keeper of the National Register, Carol D. Shull, issued a Determination of Eligibility Notification.
The main problem in determining the effects of a proposed road on nontraditional cultural properties was how to set boundaries for the preservation of "material manifestations of non-tangible values."
In his letter of May 2, 1980, State Historic Preservation Officer Mellon claimed, that "it is an essential element of ritual use that visual quality from the identified prayer seats be pristine...."
Secretary of Interior Cecil Andrus concurred that the "historic ritual use of the area constitutes 'a significant contribution to the broad patterns of our history....'" He conceded that some elements of the District lacked "individual distinction, but which together make up a significant entity." He claimed that "study of the district and its component culture and natural features is likely to yield information important in our understanding of the history and prehistory of this region." Finally, he proclaimed that criteria A, C, and D applied to the Helkau District.
(A) Destruction or alteration of all or part of a property;
(B) Isolation from or alteration of the property's surrounding environment;
(C) Introduction of visual, audible, or atmospheric elements that are out of character with the property or alter its setting;
(D) Neglect of a property resulting in its deterioration or destruction....
He omitted criterion B and included criterion C with a qualification on the audible factor, writing:
we find it impractical to define boundaries on this basis since: 1) the currently known prayer seats probably represent a small sample of those which have existed at some time . . . ; 2) safeguarding visual and auditory conditions within the district would involve a far more extensive area than currently proposed, and "safety limits" would vary considerably according to the cause of disruption.