BUENOS AIRES NATIONAL WILDLIFE REFUGE, Ariz. – In this remote, semidesert landscape along the U.S.-Mexico border, water is a precious commodity – and a contentious one, too.

Two years ago, Daniel J. Millis was ticketed for littering after he was caught by a federal Fish and Wildlife officer placing gallon jugs of water for passing immigrants in the shrub brush of this 118,000-acre preserve.

"I do extreme sports, and I know I couldn’t walk as far as they do," said Millis, driving through the refuge recently. "It’s no surprise people are dying."

Millis, 31, was not the only one to get ticketed. Fourteen other volunteers for Tucson-based organizations that provide aid to immigrants crossing from Mexico to the United States were also cited. Most of the cases were later dropped, but Millis and another volunteer for a religious group called No More Deaths were convicted of defacing the refuge with their water jug drops.

The U.S. Court of Appeals for the Ninth Circuit weighed in on Millis’ appeal this month, ruling that it was "ambiguous as to whether purified water in a sealed bottle intended for human consumption meets the definition of ‘garbage."’ Voting 2-to-1, a three-judge panel overturned Millis’ conviction.

The issue remains far from settled, though. The court ruled that Millis probably could have been charged under a different statute, something other than littering. And the Fish and Wildlife Service continues to forbid anyone to leave gallon jugs of water in the refuge – a policy backed by this state’s immigration hardliners, who say comforting immigrants will only encourage them to cross.

From 2002 to 2009, 25 illegal immigrants died while passing through the refuge’s rolling hills, flanked by mountains and home to pronghorns, coyotes, rattlesnakes and four different kinds of skunks. Throughout southern Arizona, the death toll totaled 1,715 from 2002 to 2009, with this year’s hot temperatures putting deaths at a record-breaking pace.

The Border Patrol has installed rescue beacons in remote areas along the border, including several in the Buenos Aires refuge, to allow immigrants in distress to call for help. Those who are injured and have been left behind by their guides are often so desperate they no longer fear deportation.

Still, the federal government has acknowledged that additional steps are needed to keep deaths down on its land. In 2001, it gave another aid group, Humane Borders, a permit to keep several large water drums on the refuge, each of them marked by a blue flag and featuring a spigot to allow immigrants to fill their water bottles for the long trek north.

Last year, the government considered but ultimately decided against allowing No More Deaths to tether gallon jugs to trees to allow immigrants in more remote areas to drink without taking the jugs on their way.

Right now, even after the court decision, there is what amounts to a standoff. This month, the federal government said it was willing to allow more 55-gallon drums on main pathways in the refuge. It said it would not permit any gallon jugs.

The water jugs continue to appear, though.

Last week, Gene Lefebvre, a retired minister who co-founded No More Deaths, hiked along a path popular among immigrants until he reached a clearing where volunteers for his organization had recently left some jugs.

Each bottle had markings on it noting the date it was left and the exact location on the group’s GPS mapping software. There were also signs of encouragement for the immigrants: a heart and a cross on one bottle and the words, "Good luck, companero," on another.

"We’d give water to anyone we found in the desert, even the Border Patrol," Lefebvre said.

Opponents say the water drops are encouraging immigrants to continue to come across the border illegally. The critics say there ought to be Border Patrol agents stationed near the water stations to arrest those who are crossing illegally as soon as they finish drinking. Some are so furious at the practice of aiding immigrants that they have slashed open the water jugs, crushed them with their vehicles or poured the water into the desert.

The Buenos Aires refuge is among the most troubled of the 551 refuge areas across the country, the federal government says. The reason is its location, adjacent to the border.

"Since its establishment in 1985, refuge staff have worked diligently to protect species such as the endangered masked bobwhite quail and pronghorn, as well as offer meaningful visitor recreational opportunities," a recently released government report on the water controversy said. "However, over the past decade an increasing amount of refuge time and energy has been required to address the growing issue of illegal traffic entering the U.S. across refuge lands."

In 2006 and 2007, an estimated 250,000 to 300,000 illegal immigrants crossed the refuge annually, along with Border Patrol agents pursing them, federal officials say. "As a result, refuge lands have been marred by illegal trails and roads, litter and degraded habitat," said a government report on the problem.

The numbers have dropped in recent years, to 31,500 in 2008 and about 20,000 in 2009. "This still averages approximately 50 to 60 illegal immigrants traveling through the refuge daily," the government report said.

Millis, a former high school Spanish teacher who now works for the Sierra Club, disputes the notion that leaving out water jugs is luring more immigrants. He said it was border enforcement efforts that had pushed those seeking to cross into dangerous desert areas.

As for spoiling the environment, he said he collected as many jugs as he left behind. He also recounts how he found the dead body of a 14-year-old Salvadoran girl near the refuge days before he was ticketed.

"People are part of the environment," he said.

© 2010 The New York Times Company