With ATVs, sensors, and drones, US agents fight illegal crossings, often in vain.
Inside the border patrol, they're called the "rock group" - agents, trained as welders, who spend days repairing holes in a 15-foot-high steel wall here along the border to keep out illegal immigrants. Both human traffickers and drug smugglers pay Mexican boys to use hacksaws - sometimes working all day - to cut holes in the wall, an "iron curtain" made out of salvaged aircraft-carrier landing mats. The welders respond with molten metal.
But while they're working, the agents are frequently pelted with rocks by youths on the Mexican side of the controversial wall. Hence the rock group moniker - a reference to the mini-intafada here rather than any parallel with Mick Jagger. The "boys are hurling stones today, so be careful," one agent warns us as we tour the area.
The tale of the hacksaws and the welders is a metaphor for life along the dusty US-Mexico border in an era of heightened security and expanding illegal immigration.
Up and down the 2,000-mile border, the US government is throwing more manpower and sophisticated technology into slowing illegal entries into the US. But as it does, immigrants are showing greater ingenuity in circumventing the barriers and patrols.
Now, as Congress considers another overhaul of immigration laws, the encounters and clashes along the border are likely to intensify. Most of the bills in Congress include provisions to expand the border patrol (now part of US Customs and Border Protection), which has already seen agent strength along the nation's southern flank more than double since 9/11, to 11,000.
The result is an agency that is becoming increasingly complex and unwieldy. Agents already use everything from horses to mountain bikes to all-terrain vehicles to track drug smugglers and human traffickers. They also use aerial surveillance, periscope trucks, and underground sensors. Yet, through it all, the task of stopping illegal immigration can still seem daunting, if not futile, as a day in the life of the border patrol here recently showed.