The Department of Energy has notified 12 agencies, including the nonprofit that owns the Rattlesnake Mountain Observatory, that they must move from the mountain.

"DOE does not plan to renew your existing permits, licenses, easements on Rattlesnake Mountain," said a letter sent by the DOE Hanford Richland Operations Office.

The letter, dated March 14, was signed by deputy manager Doug Shoop on behalf of manager Dave Brockman.

DOE said late Friday afternoon when the Herald obtained the letter that no one was available to comment on the new policy.

DOE will work with each tenant on the mountain to phase out existing permits, remove improvements and return the premises to their natural conditions, the letter said.

It added that DOE will work with each tenant to "minimize financial impacts by allowing time to relocate to another facility off Rattlesnake Mountain."

Until that can be done, DOE is asking tenants to limit their trips up the mountain to as few as possible. The steep, one-lane road up the mountain must be entered through a locked gate.

The letter gave no reason for the changed policy.

Most of the tenants have communication towers on the mountain or possibly power lines, but the list also includes the Alliance for the Advancement of Science Through Astronomy.

In 2005 Battelle donated the Rattlesnake Mountain Observatory, which sits on Department of Energy land, to the alliance.

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.

Rep. Doc Hastings, R-Wash., said last year that U.S. Fish and Wildlife should give serious consideration to allowing public access to the mountain as it develops a management plan for the Hanford Reach National Monument because of its unparalleled view and the observatory. The top of Rattlesnake Mountain is DOE land, but is managed as part of the monument by Fish and Wildlife.

The Alliance for Advancement of Science Through Astronomy has been operating the observatory since 1996 and has used $200,000 in donations to refurbish the telescope and dome.

The steep and winding road to the observatory is not suitable for public traffic, including school buses. But the astronomy alliance has been taking small groups of visitors to the observatory about six times a year. That includes visits auctioned to raise money for community groups.

But its goal has been to allow remote access to the observatory using computers to allow students at all levels to see through the eye of the telescope.

All systems in the telescope are computerized to eventually allow the telescope to be operated from off the site.

Other agencies that were sent the DOE letter were the Coast Guard, the U.S. Department of Justice, the Washington State Emergency Management Division, Energy Northwest, Franklin and Benton County Public Utility Districts, Day Wireless Systems, Crown Castle International, Columbia Communications, Tri-Cities Amateur Radio Club and Battelle.

Earlier this week Hanford employees were notified that access to Rattlesnake Mountain, along with access to Gable Mountain and Gable Butte, was being restricted to authorized personnel only.

In addition, new signs were posted at Gable Mountain and Butte saying "culturally sensitive area" and requiring employees to contact the Hanford Patrol before entering the area.

The announcement said a gate and signs with the same information already had been installed at the summit road up Rattlesnake Mountain. There had been "numerous unauthorized intrusions into cultural resource sensitive sites, most recently mountain biking," said the announcement, which was signed by Shoop.