The thousands of Central American migrants who have poured into Tijuana after traveling through Mexico in caravans hoping to reach the United States have strained the resources of the Mexican border city south of San Diego.

In November, Tijuana's mayor declared an international humanitarian crisis after more than 5,000 Central American migrants arrived, overwhelming migrant shelters and triggering anti-migrant protests.

On Dec. 1, the Mexican federal government was forced to intervene. It opened a second shelter on the city's outskirts when an outdoor sports complex that was being used as a makeshift shelter became dangerously unsanitary.

This wasn't the first time migrants traveling through Mexico in a caravan arrived in Tijuana, where the San Ysidro border crossing is the busiest in the western hemisphere. In April, more than 300 Central American migrants arrived in Tijuana after traveling with a caravan that initially started out with more than 1,500 but splintered into smaller groups along the way.

The April caravan was organized by the bi-national group Pueblo Sin Fronteras. The same group also organized a similar caravan that arrived in Tijuana about the same time in 2017.

But why do migrant caravans travel to Tijuana in the first place and not some other border city?

The decision to go there seems surprising considering Tijuana is 2,500 miles from Central America, twice as far as some other Mexican border cities, such as Reynosa and Matamoros, south of Texas.

And migrants traveling with caravans start out not knowing how they will reach the United States. To get there, they walk long distances, often in flip-flops or other flimsy shoes, or by hitching rides on cars and trucks, riding freight trains, or taking buses.

Experts and organizers of recent caravans from Pueblo Sin Fronteras offered three main reasons that have to do with safety, the Tijuana's network of existing shelters and humanitarian organizations, and the city's proximity to the "sanctuary state" of California.

Tijuana is less dangerous than other Mexican border cities

Because of the way the eastern end of the U.S.-Mexico border dips south along the Rio Grande, Mexican border cities south of Texas are far closer to Central America than those on the western end.

The Border Patrol apprehends more migrants from Central America in the Rio Grande Valley in South Texas than other sectors, U.S. Department of Homeland Security data show.

But to reach South Texas, Central American migrants must travel along a route along the Gulf of Mexico that takes them through several states, including Tamaulipas and Veracruz, which are notorious for criminal organizations that prey on migrants.

"I don't know how else to put it other than it's kind of a horror show," said Everard Meade, director of the University of San Diego's Trans-Border Institute.

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In 2010, 72 Central American migrants were massacred on a ranch In the state of Tamaulipas, which includes the border cities of Reynosa and Matamoros. The migrants were killed, according to a survivor's account, after they refused to pay extortion payments or refused to work as hit men for cartels that control the area.

Hundreds of graves have been found since, many of them presumed to contain the bodies of Central American migrants, Meade said.

Although migrants face threats along the entire border, the state of Tamaulipas remains especially notorious for abductions, kidnappings, extortion and robberies, said Brian Griffey, a regional researcher at Amnesty International.

"Tijuana is not safe either; it's a dangerous city," Griffey said. "But it's much safer than Reynosa or Matamoros or some of these other cities where the violence is palpable."

In Reynosa, it's common to see groups of men from criminal organizations waiting outside bus stations and shelters to kidnap migrants.

When the migrant caravan reached Mexico City in early November, organizers held group meetings to discuss which route to take to the border with the United States, said Alex Mensing, an organizer with Pueblo Sin Fronteras, which helped organize the migrant caravan after it crashed through gates into Mexico from Guatemala.

Some migrants wanted to travel to border cities in the state of Tamaulias because they are closer than Tijuana, Mensing said.

What's more, the majority of migrants traveling with the caravan were from Honduras, so traveling to border cities across from Texas would have made more sense because many of them would have been trying to reach Houston, which has one of the largest Honduran populations in the United States.

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In the end, the migrant caravan decided to head for Tijuana on a route that took them through Pacific Coastal states to avoid the dangers posed by criminal gangs in states along the Gulf Coast.

"The cartels have complete control over pretty much everything that happens in Reynosa and other border cities in that area," Mensing said. "And if you go to seek asylum and you get turned away at the bridge by Customs and Border Protection, when you walk back out on the Mexican side, you've got Mexican immigration and the cartels waiting for you. Whoever gets you first, it's not going to be good."

The Washington Post speculated that Tijuana is less dangerous for Central American migrants because the northwestern part of Mexico is controlled by the Sinaloa drug cartel. The Sinaloa cartel was built by Joaquín “El Chapo” Guzmán, the indicted Mexican drug kingpin who is now on trial in New York.

Guzman never developed the same appetite for preying on migrants as the Zetas and Gulf cartels that control northeastern Mexico.

When it came time for caravan members "to pick between a shorter route to Texas or a much longer one to Tijuana, they chose the latter," the Post reported. "One leads to the migrant version of Mordor. The other is merely dangerous."

Tijuana has more infrastructure to give migrants shelter

Another reason the migrant caravan decided to travel to Tijuana is because the city has the largest network of organizations that provide shelter and other humanitarian assistance to migrants, Mensing said.

Among the groups is Al Otra Lado — which in Spanish means "to the other side" — a bi-national group that provides legal assistance to asylum-seekers who arrive in Tijuana.

There are also about 20 permanent shelters in Tijuana run by church groups and nonprofit organizations that provide temporary housing to migrants, more than any other border city, said Maria Dolores Paris-Pombo, a researcher at the College of the Northern Border in Tijuana.

Migrants who arrived in Tijuana in the caravan's first wave didn't want to go to the shelters, she said. Instead, they headed by the hundreds to beaches near the affluent high-rise apartments in Playas de Tijuana on the Pacific Ocean, prompting confrontations with local residents.

There's a reason migrants didn't want to go to the shelters, she said. Some of the shelters in Tijuana are only for men, others are only for women, she said. Most have the capacity to hold 100 people or less.

Going to the shelters would have meant breaking the caravan into smaller groups. Migrants she interviewed told her organizers didn't want to do that, she said, because that would have made it easier for Mexican authorities, under pressure from the United States, to block them from leaving and thwart them from reaching the United States.

"That was the argument," she said.

One migrant she interviewed told her that is what happened in Tapachula, when the migrant caravan first entered Mexico in October. Several hundred migrants accepted an offer by Mexican authorities to go to the fairgrounds in Tapachula, which the government had turned into a makeshift shelter.

Mexican officials told the media the migrants had decided to stay in Mexico and apply for asylum in that country. But the migrant told Paris-Pombo "it was like a trap."

"They could not go out because they closed the door and forced everyone to ask for refuge and asylum in Mexico and they could not go outside" to join the caravan, she said.

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Paris-Pombo noted that it took the migrant caravan more than two weeks to reach Mexico City in central Mexico after crossing the border between Mexico and Guatemala but only a couple of days to reach Tijuana from Mexico City, covering a longer distance in a fraction of the time.

The migrants reached Tijuana quickly because the governors of several states in northwestern Mexico including Nayarit, Sinaloa, and Sonora, provided bus transportation, she said, citing news reports.

“We have information that the buses were paid for by the governments of the different municipalities of the states that migrants were traveling through,” Francisco Rueda Gomez, secretary-general of the state of Baja California, said after government officials decided to convert a sports complex in Tijuana into a makeshift shelter.

Paris-Pombo believes there is credibility to speculation that the governors of those states provided bus transportation not for humanitarian reasons, but because they didn't want the migrant caravan stopping in their states.

Tijuana's network of shelters, the largest of any border city, is a legacy of the city's unwanted distinction as the deportation capital of Mexico, said Maureen Meyer, director for Mexico and migrant's rights at the Washington Office on Latin America, a human rights advocacy group.

For years, the United States has deported more Mexicans into Tijuana than any other border city.

Through October, Tijuana's El Chaparral border gate, part of the San Ysidro complex, received 30,475 Mexicans who had been deported from the United States, Mexico's Office for Domestic Affairs reports. That was more than any other border city and about 17.5 percent of the 174,556 Mexicans deported from the United States during that period.

"You have in Tijuana a large network of civil society organizations and shelters that have been set up originally to support returned Mexicans but that have also been able to support asylum seekers and others that are in Tijuana," Meyer said. "It's a much bigger infrastructure than you would have in any other border area."

California is perceived as friendlier to migrants

Tijuana also has become a major destination for asylum seekers from all over the world because of its proximity to California, Meyer said.

Asylum approval and denial rates vary depending on which immigration judge is handling the case, data collected by Syracuse University's Transactional Records Access Clearinghouse show.

But a 2016 report by the Government Accountability Office, the investigative arm of Congress, found that the San Diego Immigration Court had one of the highest percentages of asylum approvals in the country for migrants in deportation proceedings.

California is also under the jurisdiction of the 9th U.S. Circuit Court of Appeals, which is generally considered more favorable toward asylum cases than those heard in the 5th U.S. Circuit Court of Appeals, which covers Texas.

"There is some truth to the fact that in the 9th circuit some immigration courts have lower denial rates," said Mensing of Pueblo Sin Fronteras.

Tijuana also is close to a network of American immigration lawyers from San Diego, about a 40-minute drive, and Los Angeles, about a three-hour drive, who provide legal advice and assistance to asylum seekers, Mensing of Pueblo Sin Fronteras said.

California is also a "sanctuary," where under state law local and state police are limited from cooperating with federal immigration enforcement authorities.

Even so, migrants trying to reach the United States. are generally unaware of how the U.S. asylum system works, said Meade, at the University of San Diego. Many are not even headed to California, but some other state, where their asylum case will be heard.

"The structure of the caravan" gives migrants an opportunity to travel together in a large group where there is safety in numbers, he said. "To a certain degree, the choice" of where the caravan ends up "is a choice really made by the organizers, not the members of the caravan itself."

Rebecca Plevin of The Desert Sun contributed to this story. Follow Daniel Gonzalez on Twitter @azdangonzalez

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