For most people, describing themselves on the U.S. Census form will be as easy as checking a box: White. Black. American Indian.

But it's not so simple for indigenous immigrants _ the Native Americans of Mexico and Central America. They often need more than one box because their ancestry can cover multiple Census categories, and they must also overcome a significant language barrier and a mistrust of government.

The Census Bureau wants to change that in the 2010 count as it tallies immigrant indigenous groups for the first time ever, hoping to get a more complete snapshot of a growing segment of the immigrant population.

In the 2010 Census, the bureau will tabulate handwritten entries specifying that the respondent belongs to a Central American indigenous group such Maya, Nahua, Mixtec, or Purepecha. The list of different populations that end up being counted will be made public when results are released in 2011, said Michele Lowe, spokeswoman for the Census Bureau.

"We're always striving to present an accurate portrait of the American people, and this is part of that effort," said Lowe.

An accurate count is important to the indigenous groups themselves, and to the federal government, which allocates resources to state and local government according to the results.

The U.S. Department of Labor estimates indigenous migrants make up about 17 percent of the country's farm workers, and may represent up to 30 percent of California's farm worker population. Florida also has a large indigenous immigrant population.

Indigenous organizations are independently working within their own communities to dispel apprehension and encourage participation in the federal survey. They speak many different languages, making a single educational campaign impossible. Some speak Spanish; some not at all.

Many have encountered discrimination in their home countries because of their indigenous origin, and in this country for their immigrant status. All this makes them less likely to volunteer sensitive personal information to a government agency.

"In the past, many people wouldn't want to say they were indigenous," said Santos Miguel Tzunum Vasquez, from the Asociacion Esperanza Maya Quiche in Florida. "Even I hid it sometimes."

Vasquez's organization was founded to help the survivors of a 1997 massacre in a village in Guatemala called La Esperanza. Guatemala's 36-year civil war left tens of thousands of civilians dead, many of them indigenous civilians who were suspected of helping insurgents.

Vasquez feels safer in the United States _ enough to look forward to telling the government of his indigenous background.