Women and children make up the few inhabitants

Granjanal is one such town.

If all its locals were home, the population would number about 600, but the absence of decent jobs at home and the prospect of relatively well-paid work over the border has snatched away all but a handful of old folk, women and children.

Family break-up

Maria Ramirez is one of those who has stayed. She struggles to keep her five children together without her husband and oldest son.

Both are working the fields in California, returning only for a short period once a year.

"It's very difficult," she said. "The family doesn't understand why their father is away. And here, they don't fear a woman. They're hard to control because there's more respect for a father figure."

Maria Ramirez sorts the dried chillies

But she also knows that her family will, inevitably, break up. Her four other sons are certain to follow the well-trodden path over the border.

Teenagers like 15-year-old Rafael say they have no choice but to go, "What else do we do?" he said.

"We have to help our families and make a life, and we can't do that here. I don't want to leave everybody behind but its not as if I can afford to worry about that."

Social impact

Silvester Martinez, a municipal official fighting the effects of migration says: "We've got huge problems because there are so many communities without men.

An old man whiles away a lazy afternoon

"So many women have to live alone without the support of their husbands, that it has a heavy social impact - we've got families falling apart, children who are out of control without a father's influence, and women who suffer from loneliness and depression."

But perhaps surprisingly, the communities don't want an end to migration - at least not in the short term.

Open borders

They are the first to acknowledge that they could not survive without the money their relatives send home from the US.

Silvester Martinez says he wants a system that allows migrants to visit their families without having to run the gauntlet of the border authorities.

"I support the proposal of Mr Fox when he says we should open the borders, and we should have temporary work visas that allow the workers to come home when they want to," he said.

Granjanal: Dearth of jobs

"We know that our men have to go, but such a system would allow them to return safely without having to risk an illegal crossing."

It is a highly charged political issue, particularly inside the US where there are fears of waves of economic refugees.

But economists like Jonathan Heath argue that the presidents of both countries should be looking closely at just such an idea.

Local economy goal

"If we try and take the politics out of it and just look at the economics, actually it makes a lot of sense.

"Our labour markets would probably complement each other a lot better than many of our politicians think," he said.

The ultimate goal of places like Granjanal is to develop their local economies to the point where migration is no longer necessary.

But until then they pray that politicians on both sides of the border will eventually find a way of opening borders to the safe and legal movement of workers.

Photography: Peter Greste