A federal appeals court yesterday struck down a management plan that allows logging on roadless areas in Alaska's Tongass National Forest, handing environmentalists a victory in the battle over wild lands in the world's largest intact temperate rain forest.

The 9th U.S. Circuit Court of Appeals in San Francisco ruled that a 1997 plan adopted by the U.S. Forest Service during the Clinton administration exaggerated the demand for Tongass timber, failed to take into account the impact on wildlife and didn't adequately consider options that called for timber-cutting in fewer roadless areas.

"This is a huge win," said Niel Lawrence, an attorney with the Natural Resources Defense Council, one of the conservation groups that challenged the plan in court. "It stops in its tracks what many people think is the most expensive, shameful and unjustified use of public lands in the country."

A Forest Service spokesman said the agency was reviewing the decision, which temporarily blocks a pending logging project and requires managers to develop a new plan for the Tongass.

"We're going to spend the next couple of weeks assessing all our options," said Tongass spokesman Dennis Neill.

The Tongass, the largest national forest in the United States, covers 17 million acres in southeast Alaska, of which more than 9 million acres are without roads. About half the roadless areas are forested, and the Tongass has been at the forefront of battles over the preservation of roadless wild lands.

The Tongass fight helped inspire a 2001 Clinton administration order barring timber-cutting and other development on roadless national-forest lands across the country.

The Bush administration in 2003 exempted the Tongass from those protections. This year, it tossed out the rest of the Clinton road ban in favor of a program that gives states a greater say over the fate of roadless areas in national forests.