Doca Espinoza, member of the caravan Realising the Hope, has been waiting for her son for more than a decade.
"My son Alberto Sadai disappeared 10 years ago. He called me last time from Chiapas, as he was planning to cross the US border. Later, I never heard from him," Espinoza told Al Jazeera.
Espinoza is just one among several women who have lost their children as they made the trip from Central America through Mexico and onwards to the US in search of a better life.
According to some estimates, about 70,000 migrants have gone missing in Mexico in recent years. Their families have not forgotten them.
" The organisation of the caravan can be a difficult task, but one of the biggest challenges once the route has started is to keep the spirit of hope in situations of extreme distress "
- Martha Sanchez
"I believe that I will find him. I have not lost the hope," Espinoza said.
Espinoza is part of a group of women from 40 to 70 years of age who are trying to draw attention to the plight of their missing loved ones.
More than 30 women - from Honduras, Nicaragua, El Salvador, and Guatemala - joined the "Liberando la Esperanza" (Realising the Hope) caravan in their quest to get back their loved ones, reaching Mexico on October 15.
Carrying the pictures of their missing children, women are travelling almost 4,600km, covering 14 states in Mexico and stopping at 23 locations during their 19-day journey.
On the way, they are asking people, shelters, hospitals, and forensic medical services if they had any leads as to the whereabouts of their children.
Some of the mothers have not heard from their children for over 20 years. But many haven't lost hope.
"It is not an easy mission," said Martha Sanchez Soler, coordinator of the Mesoamerican Migrant Movement, an organisation that has been formally enabling such initiatives since 2006. "The organisation of the caravan can be a difficult task, but one of the biggest challenges once the route has started is to keep the spirit of hope in situations of extreme distress."
When dreams becomes nightmares
Thousands of people cross the Mexican border every year chasing the "American Dream".
According to 2011 statistics released by Mexican authorities, the number of people crossing the border between Mexico and Guatemala reaches around 140,000 annually, and about 400,000 people cross the US-Mexico border.
Around 18,000 migrants coming from Central America get kidnapped in Mexican territory, according to estimates by Human Rights Watch.
Why do people risk their lives?
The reasons vary. Among the main causes are marginalisation and poverty, although insecurity has also become one of the major drivers of migration in recent years.
"Many are forcibly displaced. In Central America, the presence of the Maras Salvatrucha [a transnational criminal gang, born in Los Angeles by Salvadoran immigrants] is very strong, and people have to run for their own safety," Ana Lorena Delgadillo, a lawyer and director of the Foundation for Justice, told Al Jazeera.
In their quest for a better life, the price paid by migrants crossing Mexican territory is high - from kidnappings and extortions, to rapes, organ theft and human trafficking.
"It doesn't matter what they did to me, but what they did to other women, that's the painful part...There were 17 women, all of them returned sad, injured and hit every night"
- Anonymous immigrant
Women are more likely to fall victim to these crimes - one estimate says that they are targeted 66 per cent of the time. In many cases, women take contraceptives before travelling in an attempt to protect themselves from an unwanted pregnancy in the event of rape.
"It doesn't matter what they did to me," one anonymous immigrant from El Salvador is cited as saying in a report released to Mexico's National Human Rights Commission (CNDH). "But what they did to other women, that's the painful part …. There were 17 women, all of them returned sad, injured and hit every night."
Even children are not exempt from this gruelling experience. As border control policies tighten , family members often cross the frontier separately. As children sometimes travel alone, they can fall into the traps of criminal networks on the way.
Since 2006 kidnapping has been the most common threat on the migrant route, according to human rights and migration specialist Mauricio Farah's statements to local media.
The CNDH reported that from September 2008 to February 2009, the Commission was aware of 198 cases by which 9,758 migrants lost their freedom, often suffering extreme violence tactics.
These kidnappings are usually executed by drug cartels or criminal gangs, who demand a ransom of around $1,500 to $5,000 from the kidnappees' relatives either in the United States or in their own countries, Farah said.
If the person's relatives are unable to arrange for the "required ransom" in the "required few days", the victim will just "disappear".
Many experts also agree that migrants are being targeted by organised criminals groups. "They are forced to work with them," Ana Lorena Delgadillo said, "They are used as cannon fodder."
However, the crime networks are not the only ones responsible for these atrocities. Analysts agree that governments, through action and inaction, are also playing a role.
Sometimes, victims are rescued and the same security officers deliver them back to their captors. "The municipal police are on the criminals' side. [When I was kidnapped] they came around every day, they saw us, they could help us out, and they did nothing," said an anonymous victim according to the same CNDH report.
At least 1,230 corpses were found in 310 clandestine graves between 2007 to December 2011, reports from the CNDH indicate, earning Mexico the infamous label as "a graveyard for immigrants".
The anguish of not knowing
In the middle of this nightmare families are waiting for their lost relatives.
Telma Acevedo, a Salvadorian member of the Committee of Relatives of Dead and Missing Migrants of El Salvador, who lost track of her husband 11 years ago after he crossed the border, told Al Jazeera: "We only want to know if he is dead or alive. It will be a release to know what happened to him."
Acevedo has not participated in recent caravans, but her 70-year-old mother-in-law has.
"Sometimes we just sit down and think what could have happened to him. What if he is walking around injured? What if he just lost his memory?" she said. "We need the Mexican government to know that there are thousands of disappeared people. We need them to open their doors, we will go as far as it is required," Acevedo said.
Over the years, about 100 women have been able to reunite with their sons, some during the caravans and others as a consequence of them, Sanchez said.
"After 21 years, I found my daughter in the capital city of Mexico," Emeteria Martinez, a mother from Honduras who found her daughter in last year's caravan, told Al Jazeera.
But reuniting families has not been the caravan's only achievement - they have also attracted people's attention and put pressure on the government to acknowledge the problem.
Mothers and caravan organisers hope governments in the region will meet some of their demands: identifying missing migrants, establishing a proper data base of victims, improving security on roads and ending abuses against undocumented people.
Organisers say the caravan has been successful in drawing attention to the plight of migrants, but there is a lot of work still to be done.
"As long as there are mothers who are looking for their missing children, we won't stop our efforts. We will be there to support them," Sanchez said.
Follow Elizabeth Melimopoulos on Twitter: @Liz0210