The justices said they will not get involved in the dispute between a half-dozen Western tribes and the Arizona Snowbowl ski area north of Flagstaff. The tribes wanted to block the expansion because the resort plans to use treated wastewater to make artificial snow on the mountain.

The tribes have argued that the proposal violates a federal law on religious freedom, but the federal appeals court in San Francisco last year disagreed.

The full 9th U.S. Circuit Court of Appeals in San Francisco said the treated sewage could be used on the ski slopes, reversing the decision of a three-judge panel on the same court. The panel had held earlier that using wastewater on a mountain sacred to the tribes would violate the federal Religious Freedom Restoration Act.

The full court, however, said the tribes will still have full use of the mountain for their ceremonies and the snowmaking would not affect that. No plants would be harmed, no ceremonies would be physically affected and no places of worship would be made inaccessible, the court said.