STEVE INSKEEP, HOST:
Here is an underlying reality of the border debate. Migration to the United States across the U.S.-Mexico border is far lower than a decade or two ago. But some kinds of migration have climbed recently. For example, in Arizona, the number of migrant families arriving from Mexico has doubled in a year. And as the United States limits who may cross at legal ports of entry, many families try to cross illegally in remote areas. NPR's Joel Rose reports they hope to reach America to ask for asylum.
JOEL ROSE, BYLINE: Immigration officials recently took me to a desolate stretch of desert outside Yuma, Ariz., and showed me where more than 350 migrants and children burrowed under the steel border fence a few weeks ago.
And so they came right under here?
ANTHONY PORVAZNIK: Right here. This only goes down just about probably another foot, this - the steel. And then - so you can just dig right under it.
ROSE: Anthony Porvaznik is the head of the Border Patrol in the Yuma Sector. He says smugglers tried digging in more than a dozen different spots looking for places where the ground was soft enough.
PORVAZNIK: This is very sandy. You can see how soft this is. And it's like that all the way down, and so it was easy to dig. They dug...
ROSE: About once a week, Border Patrol agents come across migrant groups numbering 100 people or more in some of the most isolated parts of Arizona and New Mexico, miles from the nearest food, water and medical care.
JOANNA WILLIAMS: For them, the risk is worth it. They're trying to find a route to safety.
ROSE: Joanna Williams is with the Kino Border Initiative, a humanitarian group that operates a migrant shelter in Nogales, Mexico. The vast majority of these migrants are fleeing violence and poverty in Central America. Williams says federal immigration officials have underestimated how desperate these migrants are to make it to U.S. soil.
WILLIAMS: Parents, moms and dads, are trying to find the best option that they can for their kids.
ROSE: Williams says it's gotten more dangerous for them to cross in places like the Rio Grande Valley in Texas, which is controlled by cartels, so migrants are crossing in more remote border lands in spite of the risks. In December, an 8-year-old girl died in U.S. custody after crossing with a big group of migrants in New Mexico. Williams says these migrants are not trying to evade the Border Patrol. On the contrary, they're trying to turn themselves in.
WILLIAMS: And in that sense, there's not an incentive to travel in smaller groups or to try to hide from immigration officials.
ROSE: And there's another reason these families have gotten more desperate. In the past, they might have gone to legal ports of entry to request asylum. But since last year, U.S. officials have been letting only a few families in at a time. So these migrants have to choose between two bad options - cross the border illegally in remote areas or wait, sometimes for months, in border towns, where conditions can be rough, especially for young families.
In the town of San Luis Rio Colorado, right across the border from Yuma County, Ariz., hundreds of migrant families sleep out under blue tarps, the same kind you'd see emergency responders hand out after a hurricane. It's really striking. There's just tent after tent lined up all the way to the port of entry, hundreds of these blue tarps mostly, and a lot of young kids. A few feet away, two clogged lanes of traffic also wait to get into the U.S. Occasionally the drivers roll down their windows to give money to the migrants or buy them snacks from street vendors.
These migrants are afraid to leave this spot because they might lose their place in the line to request asylum. The migrants themselves keep track of everybody's place in the line in a simple spiral notebook.
HERBERT LAYAO: (Speaking Spanish).
ROSE: On this day, the notebook is in the hands of a Guatemalan asylum seeker named Herbert Layao (ph). He flips through the pages to show me the names of more than 100 families from southern Mexico, Honduras, El Salvador. He says they're waiting because they want to do this the right way.
LAYAO: (Through interpreter) To show U.S. authorities that we are able to wait, that we respect the laws of Mexico, and we respect the laws of the United States. That's why we're here.
ROSE: Layao says he's been in the line for 40 days. He says everyone he's met here has had a moment of desperation when they've thought about crossing illegally. Up and down the border, thousands have decided they can't wait. Joel Rose, NPR News, Yuma, Ariz. Transcript provided by NPR, Copyright NPR.