Artman wrote that the Timbisha Shoshone tribe "may be substantially and adversely affected by the proposed geologic repository at Yucca Mountain."

Allen Benson, Department of Energy spokesman for the Office of Repository Development in Las Vegas, said the tribe is one of 17 the agency has consulted with on Yucca Mountain matters.

"We've been working with the Timbisha Shoshone for over 10 years and look forward to continuing our relationship with the Timbisha Shoshone. ... Whether they support the project or not, it doesn't matter, we're going to work with them."

The tribe's chairman, Joe Kennedy, said the affected status decision is "a big step."

"It's been a long time coming. We're very pleased," he said this week, noting that the tribe first applied for affected status in 1998.

On a DOE-sponsored tour of the Yucca Mountain site in 2003, Kennedy described the volcanic-rock ridge as a giant snake slithering westward that "is a very scared mountain to Shoshones" and shouldn't be used as a dumping ground for highly radioactive waste.

After confirming Tuesday that the tribe had been granted affected status, he said, "I think we need to keep the government honest. ... I think some of us are saying we need to keep this thing on the up and up."

Referring to the state of Nevada and some of the affected counties that receive government funds to conduct studies and monitor the Yucca Mountain licensing process, Kennedy said, "I think we're all working for the same goal to protect the environment, protect the water, protect the land and protect the plants and animals and protect life basically so there's a future."

He said the Timbisha Shoshone tribe has trust lands in Lida Junction and Scotty's Junction in Nevada, and in Death Valley Junction, Furnace Creek and Centennial near Lone Pine in California that stand to be impacted by radioactive materials that could seep into the groundwater if they are disposed of in a maze of tunnels inside Yucca Mountain.

The tribe consists of about 330 Shoshones, he said.