IRONWOOD FOREST NATIONAL MONUMENT, Ariz. — IRONWOOD FOREST NATIONAL MONUMENT, Ariz. -- Jeannine Pallotto often rides her horse on desert trails through stands of saguaro cactus and ironwood trees crisscrossed by immigrant smuggling corridors.
Mindful of escalating violence tied to a crackdown on the border, though, she knows when to retreat from strangers.
"You never know which ones will pull a gun on you," said Pallotto, 45, who has lived next to this mountainous terrain northwest of Tucson, Ariz., for four years.
Illegal border crossings are declining because of tougher enforcement, posting an overall 27 percent drop in the four months ending Jan. 31, the U.S. Border Patrol says. All sectors on the southern border, even the nation's busiest one based in Tucson, are showing drops in apprehensions of illegal migrants.
But the crackdown has been accompanied by deadlier tactics by the most daring smugglers, who are now charging higher fees to bring Mexicans and others from Latin America into the United States illegally.
In four recent cases, seven people were killed in Arizona after smuggler-on-smuggler violence; one case is also being investigated for possible vigilantism. At Ironwood Forest this month, three suspected immigrants were killed after gunmen apparently tried to steal a rival organization's load of illegal migrants; one alleged smuggler is now in custody.
These cases have received widespread attention in the nation's busiest state for smuggling, but law-enforcement authorities, politicians and humanitarians are concerned many instances of lesser violence often go unreported.
"We have to be realistic that an unintended consequence is that the price goes up, and the unscrupulous people who see no value in human life are going to maximize their profit" by trying to hijack rivals' deliveries of illegal immigrants, said Alonzo Pena, the U.S. Immigration and Customs Enforcement's special agent in charge of Arizona.
Mexican officials said drug smugglers and illegal immigrants typically shared the same routes, but a growing turf war among Mexican drug cartels makes them less likely to tolerate migrants, especially as the U.S. beefs up border patrols.
"These are territories that the narcotraffickers need," said Dario Garcia, who works in Nogales, Mexico, for Grupo Beta, a Mexican federal agency that assists immigrants. "If they see immigrants disturbing that, what are they going to do? They take the routes away."
The Border Patrol credited additional agents, more technology and the National Guard deployment along the southern border for reducing illegal immigration, but immigrant rights advocates blamed the same measures for "militarizing" the border and creating the violence.
"Militarization has created tremendous violence here," said Isabel Garcia, co-chairwoman of an immigrant rights group called Derechos Humanos, who said she recently secured a restraining order against someone she labeled "a vigilante."
"The coyotes," she continued, referring to smugglers, "absolutely love our border policies. Now, no one can cross without a coyote, and they charge [$2,000, $3,000 or] $4,000, and [the policies] have created this tremendous profit-making industry."
The ICE's Pena counted about 65 cases between April 2005 and July 2006 in which smugglers fought over illegal immigrants through extortion, hostage-taking, or "rip-offs" of rivals' loads of illegal immigrants. The killings of migrants became a political embarrassment for Arizona Gov. Janet Napolitano this month when she visited Mexico, where officials called for an "exhaustive investigation" into the assaults on migrants.
The Southern Poverty Law Center says Arizona is its most-watched state because of immigration-related violence and vigilante activity, said Mark Potok, director of the center's hate-group monitoring project.
Last month in Phoenix, a suspected smuggler was fatally shot after an argument with other smugglers in a stash house of illegal immigrants held against their will, officials said. Also last month, two men carrying backpacks of marijuana were killed near Tubac, Ariz., in apparently in a smuggler-against-smuggler battle, authorities said.
Increased drug smuggling forced Organ Pipe Cactus National Monument, which sits on the border southwest of Tucson, to close 90 percent of its backcountry two months ago, said park Superintendent Kathy Billings.
Public lands, which along with Native American lands make up most of the Arizona border, are being ravaged by smuggling and government patrols, activists say.
"I think the damage has been colossal, and it's directly related to an across-the-board failure of U.S. immigration policy," said Daniel Patterson, a former federal Bureau of Land Management ecologist who is Southwest director of the whistleblower group Public Employees for Environmental Responsibility.
In Altar, Mexico, a staging area for migrants 60 miles south of the border, several men crowded around a peddler to read the front-page headlines about the recent slayings in Arizona, their eventual destination.
Fausto Pedroza, 34, had traveled three days from the southern Mexican state of Chiapas with hopes of reaching a factory job in North Carolina. Three times, he had boarded vans that shuttle migrants to the border town of Sasabe, Ariz. Three times, armed robbers outside Sasabe took his money. Pedroza had lost about $250 total.
"I think I'm finished," he said. "I need to go home."
Michael Martinez and Oscar Avila write for the Chicago Tribune