Thirteen nations hold this mountain sacred, and their reasons are not interchangeable.
To the Dine it is Dook'o'oosliid, the summit that never melts: the sacred mountain of the west, one of the four that bound Dinetah and fix the ceremonial geography of the homeland. To the Hopi it is Nuvatukya'ovi, the place of snow on the very top, where the katsinam dwell for part of the year. Havasupai, Hualapai, Yavapai, Zuni, Apache and Southern Paiute communities hold it under their own names and for their own reasons. Medicinal plants are gathered on it. Shrines are maintained on it.
It also carries a commercial ski area, which is how it came to be litigated.
Navajo Nation v. United States Forest Service
In 2005 the Forest Service approved a proposal allowing the Arizona Snowbowl to manufacture artificial snow from reclaimed municipal wastewater, on the order of 1.5 million gallons a day of treated Flagstaff sewage, sprayed across a mountain from which medicine is gathered.
The Navajo Nation, the Hopi Tribe and eleven other nations sued under the Religious Freedom Restoration Act. A Ninth Circuit panel ruled for them in 2007. The court reheard the case en banc and reversed on 8 August 2008.
The holding is the important part. The Act, the en banc court said, reaches only a burden that coerces a person into violating a religious belief or penalises them for practising it. Desecration of a sacred place is not that, however genuine the offence and however real the loss, so long as nobody is forced or fined. The Supreme Court declined review in 2009 and the snowmaking went ahead.
The distinction, and what it costs
Read together with the Oak Flat ruling sixteen years later, the case states the present position of American law plainly: religious-freedom protection attaches to a practitioner's conduct, and has repeatedly declined to attach to the ground the practice requires.
For traditions built around portable observance, that distinction costs nothing. For traditions in which the ceremony is tied to a particular mountain and cannot be performed anywhere else, it is the whole of the problem, the protection is drawn in a shape the religion does not fit. That is the criticism made by Vine Deloria Jr. and by tribal legal scholars since, and the cases have borne it out rather than answered it.