The latest battle in the war on illegal immigration isn't over the smuggling of undocumented workers, it's over the trash they leave behind.
Government officials and border activists say the garbage dumped in the desert by illegal immigrants and their smugglers is staggering.
And the cleanup is costing taxpayers millions.
In 2006 alone, more than 1.18 million pounds of trash was collected along southern Arizona border, many in the meeting spots where immigrants rest, change clothes and wait to hitch a ride further north with a smuggler.
"You can find everything," said Shela McFarlin, special assistant for international programs at the Arizona Bureau of Land Management. "Blankets, airline tickets, Bibles, wedding pictures, photos of children, school reports, because clearly people don't tend to throw away everything they've brought with them — they're forced to."
Arizonia officials have spent approximately $4.4 million over five years to clean up the mess, that continues to build with each crossing. Nearly $1 million was spent for 2007 from a base BLM appropriation.
Border Patrol's Tucson sector, which covers most of the Arizona border, doesn't have statistics about how many people cross through each year, but on average, agents apprehend 1,500 people a day, with 378,000 undocumented immigrants caught in 2007 alone.
The trash is a problem that activist groups, like the Minuteman Civil Defense Corps, say will not stop until the nation's southern border is secured.
"It's just like a flood," said Chris Simcox, the president of the Minuteman Civil Defense Corps. "You can't clean up the floodwaters until you stop the flood and fix the dam."
Successful efforts by the Border Patrol to secure well-trafficked crossing spots in San Diego and El Paso have forced many immigrants to cross through federal and state lands along the Arizona border adding to the trash problem, McFarlin said.
Since 2003, the Arizona BLM has run a project to mitigate the damage caused by the migration of illegal immigrants along the state's border with Mexico.
"What we're beginning to wonder is how extensive is the problem?" McFarlin said. "How many millions of pounds of garbage? How many roads are really damaged? How many miles of illegal trails?"
McFarlin's agency works with local government, student volunteers and civic groups to bag trash in wilderness areas frequented by immigrants. The BLM also disguises smuggling roads by planting new vegetation over the desert tracks carved by smugglers.
"The first thing you notice if you were to drive across some of this land is you see water bottles, lots of water bottles," McFarlin said. "Where people stop to wait to be picked up — we call them 'layup' spots — then you will see more of the clothing, medicine bottles, papers, everything.
"We recently cleaned up one location with almost 4,000 backpacks left behind," she said.
Simcox said his group cleans up the private lands of ranchers who help them on their quest to monitor the border.
"We've seen it time and time again, where we go in and clean up these areas and within months they're just filled again with the same debris," Simcox said.
The Arizona BLM and the Minuteman Civil Defense Corps do not work together on cleanup efforts.
Both groups say it may take years to correct.
"Truly, it's a national disaster of our cherished outdoor areas," Simcox said.