FLAGSTAFF, Ariz. -- Some American Indian advocates are calling on forest service officials to reverse their support for snowmaking plans at the Arizona Snowbowl.

``We as indigenous people will not tolerate further desecration of our sacred peaks,'' said Havasupai tribe cultural director Rowland Manakaja during a news conference in the Flagstaff City Council chambers.

More than a dozen speakers at the conference urged the U.S. Forest Service to rethink the plan. Officials from the agency, which supports creating more snowmaking and adding runs at the Arizona Snowbowl, were not present at the event.

Several tribes oppose the plan to use reclaimed wastewater to make snow on the San Francisco Peaks, saying it desecrates the sacred site.

Adding man-made snow to the peaks falls out of line with Hopi tribal beliefs that say katsina spirits grant the rain and snow.

Also, traditional practitioners who gather herbs from the mountains for ceremonies worry how the reclaimed water could affect plants they believe have spiritual properties.

An environmental impact study released by the Forest Service suggests the impact of snowmaking and upgrades to culturally sensitive sites can be mitigated by consulting with tribal leaders to ensure religious practices aren't interrupted.

``These concerns are focused on the spiritual and cultural issues, not the actual biological purity of the water itself,'' according to the statement.

Poor snowfall since the mid-1990s has financially hurt the 777-acre ski park. Snowbowl operators say they need guaranteed snow for the park to survive.

Flagstaff, which plans to sell reclaimed water to the Snowbowl if the plan is approved, could also be targeted by opponents of the measure.

``This is serious enough to where we will be starting some mobilization efforts to boycott the city of Flagstaff,'' said Cora Max, an aide to Navajo Nation President Joe Shirley Jr.