MOUNT VERNON, Wash. (AP) - When immigration agents arrested 16 farmworkers in a mass arrest of illegal immigrants early this year, legal advocates raced to find interpreters for the men, who spoke only a language called Mixtec.

But by the time an interpreter was found, most of the men were on their way out of the country after signing away their rights to contest deportation - a procedure they might not have understood.

The deportations alarmed immigrant advocates in this agricultural city 60 miles north of Seattle. It also raised questions about the deportation proceedings for people who speak little Spanish or English.

"There is no way they knew what they were signing. No way," said Rev. Jo Beecher of the Episcopal Church of the Resurrection in Mount Vernon, one of the advocates who tried to help the men.

Although federal courts have ruled that immigration proceedings must be translated into the language of the detainee, U.S. Immigration and Customs Enforcement has no interpreters in the area who speak Mixtec - a tonal language with several dialects - Beecher said.

The case of the Mount Vernon men also highlights some of the clashes that are becoming more common as the growing community of indigenous peoples from Latin America meets the American legal system.

Indigenous peoples are the direct descendants of the inhabitants who lived in the region before colonial times. They have a distinct culture, languages and history than those of their Latino counterparts.

Some observers believe the migration of indigenous Latin Americans to the U.S. is increasing even as the flow of Spanish-speaking immigrants eases.

There are about 500,000 indigenous people in the U.S., according to the Bi-national Center for the Development of the Oaxacan Indigenous Communities, based in Fresno, Calif. That's only counting people from Mexico, not other countries such as Guatemala, El Salvador or Honduras.

Between 10 and 30 percent of the farm workers in California are now estimated to be indigenous, a recent study by the U.S. Department of Agriculture found. Similar growth has occurred in Washington, Oregon and Florida.

"It's been until recently that the immigration has grown to a point that the government has become aware of the language diversity," said Gaspar Rivera-Salgado, a project director at the Center for Labor Research and Education of the University of California Los Angeles. "As more and more immigrants arrive ... authorities are not very well prepared."

Hundreds of indigenous languages and dialects are spoken in Mexico and Central America, and some of those dialects are drastically different from each other, said Rufino Dominguez-Santos of the Bi-national Center for the Development of the Oaxacan Indigenous Communities.

In Oaxaca alone - the Mexican state where the bulk of indigenous workers in Mount Vernon have come from - twelve different languages are spoken, Dominguez-Santos said. Fourteen percent of Oaxacans who speak an indigenous language don't speak Spanish, according to Mexican census figures. Mexico's government recognizes 162 living languages, plus some 300 dialects.

"There's a lack of knowledge by immigration agents, police and social workers that there are a lot of languages spoken in Mexico," Dominguez-Santos.

In the Mount Vernon case, agents quickly recognized that the group didn't speak Spanish, said Lorie Dankers, ICE's spokeswoman in Seattle.

But the son of one of the arrested men arrested volunteered to translate, and did so when 14 of the men chose "voluntary return," an option that lets illegal immigrants leave the U.S. quickly, avoiding detention and other sanctions, such as a 10-year entrance ban to the U.S.

"The supervisor observed the interview, based on the body language, he believes they fully understood," Dankers said.

ICE also has the option of contacting an interpretation service run by Philadelphia-based Language Services Associates, which says it has the ability to furnish interpreters for Mixtec and six other indigenous languages.

Using someone in the community is a common practice among law enforcement and other government agencies, but it can lead to trouble and misunderstandings. In many instances, concepts of American law don't translate easily into indigenous law and should be conveyed by a trained interpreter, Dominguez-Santos said.

"If you have a document where you purport to be giving up certain rights, then you have to have that document translated in a language you can understand in order for the process to comply with due process," said Jorge Baron, an attorney and executive director at the Northwest Immigrant Rights Project, a Seattle-based legal aid group. Baron's group helped in finding an interpreter for the men.

But Mark Krikorian, executive director of the Washington, D.C.-based Center for Immigration Studies, cautions that access to interpreters for immigrants facing deportation is not a right.

"To think it's a right, our responsibility, to help you avoid being deported, it's kind of silly," Krikorian said. "If we don't have a translator in your obscure language, well, that's too bad."

His organization lobbies for stricter immigration enforcement. He said that bringing up the language barriers is a tactic by immigration attorneys to delay deportation.

The whereabouts of the men deported is unknown.

ICE agents found the men by knocking on the doors of crammed rooms inside old rundown homes that house indigenous farmworkers during the offseason here. The agents were looking for one woman who had failed to leave the country as ordered. They ended up arresting 16 people.

ICE did not deport the 16-year-old who was detained, and now the teenager is in foster care, while family friends try to gain temporary custody.

The woman they initially sought was never found.

Copyright 2009 The Associated Press.