FRESNO, Calif. (AP) _ Yosemite National Park must halt more than $100 million in planned construction projects because the developments threaten the park's fragile ecosystem, a federal appeals court panel ruled Thursday.

Work on moving campgrounds, rerouting a key access road and upgrading hotel rooms on Yosemite Valley's floor had been temporarily barred since a U.S. District Court ruling last year.

The decision by a three-judge panel of the 9th U.S. Circuit Court of Appeals means the repairs must stop until September 2009, when the agency is due to produce a new plan to manage the federally protected Merced River.

The river courses alongside the valley's cherished granite walls and glimmering waterfalls.

Yosemite officials said they feared the ruling could push the park service to cap the number of people allowed through the gates each day in order to safeguard Yosemite's natural resources.

"The implications here for Yosemite and all national parks are huge," park spokesman Scott Gediman said.

The two small conservation groups that filed suit in 2000 had long argued that the government's plan to manage the California black oaks, delicate wetlands and bat species that thrive near the riverbanks was inadequate.

"This is really more about preserving everyone's access to the park than it is about denying access," said Bridget Kerr, a member of Friends of Yosemite Valley. "I have always had hope, but I have even more hope now that the American citizens will have a voice in protecting Yosemite."

After the Merced flooded in 1997, park officials drew up an ambitious remodeling project to move campgrounds and fix roads destroyed by the river. The plan would have blasted part of the river canyon and felled nearby oaks.

Friends of Yosemite Valley and Mariposans for the Environment and Responsible Government sued, saying the park's plans would allow rampant commercial expansion that could degrade the valley's health.

Thursday, the court said the park service had broken federal law "by not requiring a response to environmental degradation until after it already occurs," Judge Kim Wardlaw wrote.

Copyright 2008 The Associated Press.