The future of Rattlesnake Mountain was set in 1999 when a decision was made based on a comprehensive land-use study to manage the mountain for preservation, according to the Department of Energy.

On March 14, DOE sent letters to 12 agencies, including the nonprofit that owns the Rattlesnake Mountain Observatory, saying they must remove structures from the mountain.

"It really is a continuation of a land management decision DOE made," said Matt McCormick, DOE assistant manager for central Hanford cleanup. "We're phasing out uses not consistent with preservation land uses."

But a decision of that magnitude should not be made without public input, and public input provided more recently than nine years ago, said Roy Gephart, president of the Alliance for the Advancement of Science Through Astronomy, or AASTA, which owns the observatory.

"What this letter means to AASTA is the largest observatory in the state of Washington and a unique educational asset will be removed," he said. "There is no place to put it and no money to move it."

DOE said in the letters to tenants on the mountain that their existing leases or easements on the mountain would not be renewed, but it would work with agencies to minimize financial impacts and allow time to move to other locations.

Most of the agencies have telecommunication towers on the mountain under five-year leases. Three of the leases already have expired.

However, the observatory has no lease. Instead, Battelle, which donated the observatory to AASTA in 2005, had a permit to use the DOE land and DOE has retained the right to terminate the permit.

The letter saying that manmade structures would have to be removed from the mountain came after 21⁄2 years of work by AASTA to gain a lease, Gephart said.

In October 2005, DOE canceled an event planned by AASTA and said it must have a lease before allowing any public access, Gephart said. After years of supplying information and at one point receiving a draft lease from DOE that needed a minor change, AASTA received the March 14 letter without warning, he said.

Before the years spent working on a lease, AASTA had raised $200,000 in donations for insurance, to buy new equipment and update the facility, Gephart said. It also used small tours to the observatory to raise money for community organizations, including $8,000 for the Mid-Columbia Symphony in 2005.

"It has been a wonderful asset to the community," he said.

The observatory is reached by a steep, one-lane road with a locked gate. But AASTA's plan has been to supplement about six small tours a year by offering remote access to schools through computerized equipment at the telescope.

Battelle Memorial Institute built the observatory in 1971 using private money for astronomical research. Its 0.8-meter Cassegrain telescope remains the largest telescope in the state, according to the American Astronomical Society.

Relocating the observatory would require hundreds of thousands of dollars, Gephart said. And finding another suitable location would be difficult.

"Research-grade telescopes are put on mountains for a purpose," he said. Rattlesnake Mountain, which stands about 3,600 feet above sea level, gave the telescope a platform above dust and low-hanging clouds.

DOE has yet to start discussions with AASTA about the observatory.

"We will negotiate with each individual based on circumstances," said Boyd Hathaway, DOE realty officer.

Rattlesnake Mountain was designated for preservation for protection of its ecological and cultural resources, he said.

The mountain is part of the Arid Lands Ecology Reserve, part of a security perimeter created in World War II when the Hanford nuclear reservation began to produce plutonium for the nation's nuclear weapons program. Because the DOE portion of the mountain has been closed to most of the public since then, it remains relatively pristine.

The top of the mountain is ecologically sensitive, said Greg Hughes, U.S. Fish and Wildlife manager of the Hanford Reach National Monument, which includes the Arid Lands Ecology Reserve. Winds blow up to 100 mph there and only a thin layer of soil covers the rock, but plants grow there that have specially adapted to the ecosystem, he said. The mountain top also is historically and culturally important to area tribes, he said.

Fish and Wildlife has been concerned that the road to the top of the mountain is not suitable for public traffic and could be expensive to maintain. It has released a draft management plan for the monument, which also considered the possible fate of the observatory, but has not released the final management plan. DOE owns the monument land but it is managed by Fish and Wildlife.