A ski resort’s plan to use treated sewage to make snow on a mountain sacred to Native American tribes was blocked yesterday by a US federal appeals court, after emotional objections by tribal leaders.

The Arizona Snowbowl, 150 miles (240km) north of Phoenix, has been in business since 1938 but suffers greatly from unreliable snowfall, not helped by recent mild winters. During the 2001-02 winter season there were only four days when skiing was possible at the resort.

Owners of the resort said that artificial snow to enable skiing throughout the winter is crucial to its economic survival.

Native American tribes, however, say that the plan violates their sacred land and America’s Religious Freedom Restoration Act, which rules that the federal government may not “substantially burden a person’s exercise of religion”.

The dispute over the sewage-based snow is one of the most prominent in recent years pitting the religious beliefs of Native Americans against economic interests.

According to the Navajo Nation tribe, the San Francisco Peaks, where the Snowbowl is located, are sacred to more than 13 Native American “nations”.

“They walked all over our dignity,” said Joe Shirley Jr, the Navajo Nation President, when objecting to the plans in 2005. The operators of the Snowbowl, meanwhile, said that artificial snow was essential to creating a viable business and ensuring the area’s economic survival. But a three-judge panel of the 9th U.S. Circuit Court of Appeals disagreed.

“We hold that the Forest Service’s approval of the proposed expansion of the Snowbowl, including the use of treated sewage effluent to make artificial snow, violates RFRA,” concluded the panel yesterday.

This overruled the decision last year by a US District Court judge to allow the $25 million (£13 million) upgrade to the Snowbowl, a 777-acre resort located on federal forest land. This would have included the use of treated sewage water.

The Navajo Nation, which has an estimated 300,000 tribal members in Arizona, New Mexico and Utah, joined other tribes and environmental groups to fight the decision. The appeals court panel noted the religious significance of the Peaks to the Navajos, Hopi, Hualapai, Havasupai tribes, among others, and discussed how sewage is treated to make reclaimed water.

“The record supports the conclusion that the proposed use of treated sewage effluent on the San Francisco Peaks would impose a burden on the religious exercise of all four tribes discussed above – the Navajo, the Hopi, the Hualapai, and the Havasupai,” wrote Judge William Fletcher.

“We are unwilling to hold that authorising the use of artificial snow at a functioning commercial ski area in order to expand its facilities, as well as to extend its ski season in dry years, is a governmental interest of the highest order.”

Times Recommends

• No cause for celebration in crushed Sarajevo
• Jazz funeral for the final victims of Katrina
• French fined for 'insulting' civil servants