Attorneys for thousands of American Indians who claim the government squandered $137 billion in royalties from their land over more than a century want a judge to set deadlines for a government accounting and better management of the system.

Interior Department attorneys countered with a proposal to account for the money that will cost an estimated $335 million over five years.

U.S. District Judge Royce Lamberth ordered both sides to craft plans on how to fix the trust, which has been plagued with management problems since 1887. The proposals were submitted to the court shortly before midnight Monday and a hearing is scheduled for May where the judge will decide what action, if any, should be taken.

In 1887, Congress assigned small allotments of land to individual American Indians and gave the Interior Department responsibility for managing the oil, gas and timber royalties from the land.

But the money was poorly managed and in some cases never collected and the American Indians suing the government claim the mismanagement cost more than 350,000 Indians billions of dollars.

The plaintiffs' court filings say the losses could be at least $40 billion, but experts hired by the plaintiffs say the figure could be far higher, as much as $137 billion.

The Interior Department acknowledges the money was mismanaged, but says the amount lost is much lower. The department estimates that about $13 billion in Indian royalties have been collected since 1909.

In 1999, Lamberth ordered the department to account for the money and repair the management flaws. Last September, Lamberth, frustrated with the department's progress and reports to the court that he said were fraudulent, held Interior Secretary Gale Norton in contempt of court.

The department now plans to do a transaction-by-transaction accounting of the money in the largest of the Indian accounts and do a statistical sampling of enough of the smaller accounts to pin down the amount owed within 99 percent, Deputy Interior Secretary Steven Griles said Monday.

In the Indians' filing, attorney Dennis Gingold said so many documents have been destroyed or lost that the department's accounting is impossible, and urged the court to order an analysis similar to the one they commissioned that produced the $137 billion estimate.