If you're planning a trip to one of America's national parks soon and browsing the Web for information, don't bother going to the National Park Service's official sites. They're all down.

They, along with the entire network of Web sites operated by the U.S. Department of Interior, were inaccessible Friday following an order by a U.S. District judge who feared flimsy security might have contributed to the loss of billions of Native American Indian trust monies.

Employees with agencies in the department were notified of the shutdown Thursday. E-mail operations are also interrupted.

It is unclear how long the blackout will last.  Judge Royce C. Lamberth ordered Department Secretary Gail Norton late Wednesday to immediately shut down Internet access from any computer, server and system in the department that has access to individual Indian trust data.

In response to the order, the department has shut down its e-mail and more than 100 Web sites including those for the U.S. Fish and Wildlife Service, the National Park Service, and the Bureau of Land Management. None of the sites were accessible Friday.

BLM spokeswoman Celia Boddington said she could send e-mail to other BLM employees, but could not contact anyone outside the bureau.

Lamberth, who has presided over a long-running lawsuit accusing the federal government of losing more than $10 billion in Indian trust money over the last century, ordered the shutdown after a hacker hired by a court-appointed investigator broke into the trust fund twice without much effort.

"Without such direct oversight, the threat to records crucial to the welfare of hundreds of thousands of (Indian) beneficiaries will continue unchecked," investigator Alan Balaran wrote in a statement to Judge Lamberth.

The computer system currently tracks $500 million a year in royalties, rents and other income from 54 acres of land held in trust by the DOI and its Bureau of Indian Affairs since 1887. That money is supposed to be doled out methodically to Indian beneficiaries, but as the lawsuit contends, much has been mismanaged, lost or downright stolen over the decades.

Balaran said his hacker merely used a normal Internet connection and free software to get into the system. Once inside, he said, there were no firewalls and or anything installed to detect intruders. Another hacker hired by the DOI found the same shortcomings in the system.

Dennis Gingold, the attorney who asked the judge for the order, said Interior didn't need to take such a sweeping approach to comply with the judge's order.

"This just shows you how inept they are," he said. "They don't even understand how these systems relate to each other so they just pull the plug on the entire system."

Secretary Norton, who inherited the lawsuit initiated during the Clinton administration, is expected back in court Dec. 10 to defend her office against contempt of court allegations.

She is charged with showing that her office complied with Lamberth's 1999 order that the Interior Department piece together how much is owed to 300,000 Indians who sued the agency. Norton also must prove that she did not file false or misleading reports about the status of the accounting and the department's current system of tracking the Indian royalties.

In 1999, Lamberth held former Interior Secretary Bruce Babbitt and former Treasury Secretary Robert Rubin in contempt and fined them $600,000 for failing to produce documents in the case.

He also ordered Interior to fix the system and account for the lost money, but so far the department has failed to do either despite spending $614 million on the effort, according to reports by court-appointed watchdogs.

At an Oct. 30 hearing, Lamberth scolded the Interior Department's lawyer and advised the lawyer to "throw yourself on the mercy of the court," rather than defending conduct he called "so clearly contemptuous."

The Associated Press contributed to this report