In my post of 10 Jun 2014 GCNP BOUNDARY E: HAVASUPAI (ADDITIONAL INFORMATION); BEAVER FALLS MYSTERY, IN 3 PARTS", I traced the current situation where the Havasupai have laid claim to Havasu Creek below Beaver Falls, a claim that appears on all maps I have found so far.
However, in my recounting of the legislative history of PL 93-620, I uncovered (well, re-covered) the information contained in the Report of the House Interior Committee on S.1296, that the boundary of the Reservation, as described on the official map, is explicated this way:
"Such map, which shall delineate a boundary line generally one-fourth of a mile from the rim of the outer gorge of the Grand Canyon of the Colorado River and shall traverse Havasu Creek from a point on the rim at Yumtheska Point to Beaver Falls to a point on the rim at Ukwalla Point…" (my emphasis); the map having been named earlier in the Act as 113-20,021B, dated December, 1974.
AND in its Section-by-Section Analysis, the Report on page 11 reads:
"All of the lands to be transferred by section 10 are outside the perimeters of the main stem of the Grand Canyon; however, the boundary crosses one major tributary canyon at Beaver Falls. It is the intention of the Committee that in establishing the precise boundary for the park at this point that the Secretary should cross UPSTREAM from the falls in order to assure their protection as a part of the park." (my emphases throughout).
Therefore, the full House, in accepting the Havasupai land grant amendment in Section 10, without any discussion of the boundary, implicitly accepted the interpretation of the Committee of the upstream crossing of Beaver Falls.
The story I am telling of PL 93-620 has now progressed to the Senate-House Conference, which took up the differences between what the two houses had passed, debated them, and fashioned the legislation in its final form, as I tell elsewhere. That Conference produced its own report. It is dated 17 Dec 1974, and was taken up and agreed to by the House on the 18th. Here is the relevant section of the "Joint Statement of the Committee of Conference" on page 6 under "(3) Havasupai Reservation Enlargement":
"The House amendment included a provision for an immediate enlargement of the reservation and specified that the boundaries would be located on the plateau one-quarter of a mile from the rim of the canyon except where it crosses Havasu Creek from Yumatheska (sic) Point to the top of Beaver Falls to Ukwalla Point; thus granting trust title to approximately 185,000 acres of national park, monument and forest land to the Havasupai Tribe." (my emphasis)
It is significant that the Conference did make some modifications to Section 10 but the boundary was not the subject of discussion. It thus was accepted by both the House and Senate Managers and recommended to their respective bodies. That is, to belabor the point, first the House Committee, then the full House, then the Conference, then the House and Senate each considered and approved, with explicit statements in the two Reports, that Beaver Falls was to remain in the Park.
I would go so far as to say that those legislators of , oh, so long ago, insisted on, were adamant about, Beaver Falls staying in the Park. And even though we have all moved on and are more enlightened, pleasant, and of sweeter disposition than 40 years ago, the National Park Service administrators of Grand Canyon National Park ought now to obey the law and assert the Nation's ownership of Beaver Falls, doing whatever is necessary to assure public access, and at the same time, removing and preventing any vandalism to this land, that, even had it been under Havasupai supervision, the legislation said should be "forever wild".
Sources: Various congressional documents as indicated