Peyote is used by Plains Indian members of the Native American Church. For them, it is semi-legal. Like marijuana, however its use has spread.
The only pueblo society that uses it in ritual is Taos; they got it from Oklahoma Indians about 1907, a late variation to some of their ceremonials.
Some Navajo use it, but usually only those who have taken up the Native American Church. It has not become a part of their ceremonies.

Some Hopi individuals use peyote, mostly those who have left the home reservations, but it is frowned upon by most tribal members.

Studies seem to indicate that it has no permanent effects on the user. A court in New Mexico threw out a case against a non-Indian who was supplying peyote to members of a Native American Church, they accepted that he was supplying it for religious purposes. I know of no further attempts to block its use there.