Representatives Lynn Woolsey and Mike Thompson are siding with Sonoma County against federal recognition for Alexander Valley's Wappo Indians, arguing the Interior Department has no power to restore the Wappos' tribal status.
The two members of Congress said they fear the tribe will open a new Indian casino in Sonoma or Napa counties, endangering world-class vineyards.
"The stakes in this matter not only raise constitutional issues ... but serve to threaten the fundamental basis of the region's economy," they said in a letter last month to Interior Secretary Kenneth Salazar.
The letter also was signed by Rep. Don Young of Alaska, who heads the House subcommittee on Indian affairs.
Wappo chairman Scott Gabaldon on Monday called the letter a political move to block his tribe's fight for justice in U.S. District Court. It won't succeed, he said.
"I don't think it will affect the lawsuit," he said. "They are blowing everything out of proportion."
The Wappos have no plans for gaming, but they would get the right to open a casino if their lawsuit is successful, he acknowledged.
"We can't decide anything until we get our federal status," Gabaldon said.
The tribe sued the Interior Department in 2009, charging the government acted unlawfully when it disbanded the tribe in 1959. The Bureau of Indian Affairs established a 54-acre reservation for the Wappos in Sonoma County starting in 1908.
Known as Alexander Valley Rancheria, it was located on the Russian River northeast of Healdsburg. But the tribe lost its federal recognition 51 years later when Congress passed a law aimed at privatizing California's small Indian communities.