WASHINGTON - A former U.S. interior secretary on Monday joined a lengthy list of environmentalists who oppose the Warm Springs tribes' proposed Cascade Locks casino.

Cecil Andrus, former secretary of the interior and former governor of Idaho, sent a letter Monday to current Interior Secretary Ken Salazar, urging the government to consider the scenic qualities of the Columbia River Gorge when it decides whether to allow a new casino.

With only a few months remaining until the Bureau of Indian Affairs releases its final report on the casino's projected environmental impact, Andrus gives environmental groups another big name in their public relations campaign against the proposal.

Friends of the Cascade Gorge have led the anti-casino campaign, but they were joined by the Oregon League of Conservation Voters, Oregon Wild, Greenpeace, the National Audubon Society and others that signed on to Andrus' letter.

In a phone interview from his home in Boise, Andrus, 77, said he's concerned a casino - and the hundreds of thousands of cars it would bring - would hurt air quality around the Gorge.

Andrus, who served as interior secretary during the Carter administration, grew up in Hood River and said he remembers the Gorge as it used to be - including Celilo Falls, before it was wiped out by dams.

"I'm old enough to remember before that was inundated by (The Dalles) Dam. As a kid we used to go there and watch the Native Americans fish," Andrus said. "That's not a place to put a 600,000-square-foot casino with all of the adverse environmental things that go with it."

The Warm Springs tribes have proposed building a nearly $400 million casino and resort in the Gorge, less than 45 miles from Portland. The facility would be about 75 miles from the northern border of the reservation.

The Warm Springs proposal is backed by Oregon Gov. Ted Kulongoski and the Cascade Locks City Council. The tribes own land near Hood River where they have the right to develop a casino, but that land is generally considered more environmentally sensitive than the Cascade Locks industrial land on which they hope to build the proposed casino.

Kulongoski endorsed the Cascade Locks site, in exchange for a percentage of casino profits and a promise not to develop the Hood River land.

Howard Arnett, an attorney for the Warm Springs tribes, said opponents of the project should wait for the Bureau of Indian Affairs to complete its environmental impact statement before making claims about the casino's impact.

"We think the decision will be made based on the law and the facts that are developed in the record," Arnett said. They're jumping the gun if they're saying this is what's going to be the consequences."

Visits with lawmakers convinced Andrus to sign on to the anti-casino campaign, he said.

"I went back to Washington, D.C., and met with some members of Congress, and it became apparent to me that nobody is championing the cause of the Gorge itself," Andrus said.

In Oregon's U.S. House delegation, Rep. David Wu, D-Portland, has publicly opposed the casino, although it's outside of his Congressional district. Rep. Greg Walden, R-Hood River, has supported the casino proposal.

The Bureau of Indian Affairs hopes to release a final environmental impact statement within a few months, said Scott Aikin, division chief for natural resources in the BIA's Northwest region.

In all, it will be about eight months before the bureau decides whether to approve the Cascade Locks casino, Aikin said.

If the Warm Springs application gains approval from federal agencies, the casino would be the closest Oregon casino to the state's biggest metro area.

Currently, the closest casino to Portland belongs to the Confederated Tribes of the Grand Ronde, who operate the Spirit Mountain Casino, located west of Salem. Warm Springs Tribal Council members have called the project crucial to the economic well-being of the tribes.