In a victory for Native American tribes, an appeals court ruled Thursday that states cannot use negotiations for a Native American casino to challenge the federal government's decisions to recognize a tribe and set aside land for it.

An 11-judge panel of the 9th U.S. Circuit Court of Appeals said states have to use a separate process to contest those decisions and have a window of six years to file their challenge.

The decision removes the uncertainty many tribes faced about their land status after a smaller 9th Circuit panel reached a different conclusion, said Joe Webster, a partner with the Washington, D.C.-based law firm of Hobbs Straus Dean & Walker who was closely watching the case.

"This is certainly an important decision for tribes," he said.

The ruling came in a fight between California and the Humboldt County-based Big Lagoon Rancheria over the tribe's plan for a Las Vegas-style casino.

The tribe accused the state in a lawsuit of failing to negotiate a casino deal in good faith, and largely won its case in federal district court. A call to the state attorney general's office for comment about Thursday's ruling wasn't immediately returned.