It felt like we were back in the Middle East, but this was much closer. Our crew, three of us, arrived at the border southeast of San Diego late in the morning.

The location, an abandoned Korean-War-era Air Force landing strip, had seen better days.  This is the home of the U.S. Border Patrol's Air Mobile Unit, the only one like it along the turbulent line seperating the U.S. and Mexico..

The men were outfitted like many U.S. soldiers currently in Iraq. Wearing green uniforms and carrying special packs holding water, food and other supplies, these men are ready for the difficult elements that are included in such treacherous terrain. 

Their unit bases its training and missions on other Special Operations teams within the U.S. government, but these men have little of the special treatment or equipment. Their makeshift office -- tacked-on to a silverish rusting hangar -- remains outdated and certainly not large enough to hold men with such a daunting task.

Their mission is to stop the thousands of illegal immigrants that make the hike across the border into the United States. The terrain they cover runs from the beaches of the Pacific, across mountains nearly 5,000 feet high and eventually ends in the middle of the desert.

U.S. officials have long been challenged with how to confront the problem of illegal immgrants, especially those from Mexico. On Wednesday, President Bush proposed a controversial plan that would allow illegal immigrants working in the United States to stay here if their employers vouch for their jobs.

Those on the front lines charged with stopping the illegal flow across the U.S.-Mexican border are dedicated to their jobs. And their backgrounds as varied as the terrain they are in charge to cover. Agent Chuck Albrecht says the agents may all be Americans, but many have immigrated here, from Latin American countries as well as from Europe.

The men give up months of their lives and come to the unit prepared. "What you have here is a number of highly motivated agents," Albrecht said. "I would say a little above average
intellect, very physically fit and very competent in field craft."

After a quick meeting to discuss their latest mission, we board a huey helicopter that once served the U.S. military during Vietnam. Now it is periodically loaned to the Air Mobile Unit to help lift personnel into areas that would normally take hours to get to.

On this day the sun had no cloud cover. Its brightness bounced off of the barren and jagged hills that rise from the main Tijuana border crossing heading East towards Arizona. Our flight path follows the border and the fence that extends for a few miles before its abrupt end right as the mountains begin to rise.

Much of this area was recently burned, and what's left of the chaparral can barely be seen. The hills have a grayish tint to them, the dust and soot kicking into our eyes as we land opn a plateau at an altitude of about 3,000 feet. The three of us -- my producer Elka Worner, photographer Eric Barnes and I -- quickly exit on the high side of the helicopter so we won't get clipped by the blades. Joining us are four agents wearing garb that will help them in these tough conditions.

Once the helicopter takes off, headed back to the base to pick up other agents being deployed onto other hilltops, we begin to hike down towards the border. Our eventual embed point is a ledge that looks out over a small creek that serves as a makeshift border.

Here, the men dig in.

They cover themselves with a mesh net that camouflages their location. Each has binoculars trained onto the area where so many illegals have passed; trails are worn into the rocky, rugged hillsides. Here the men will stay, sometimes for days, this time for hours. They're patient, waiting, looking for anyone trying to come across without permission.

"We have an added and important job," one agent said. "We have to watch for illegals and we have to keep an eye out for terrorist activity."

Adam Housley joined Fox News Channel (FNC) in 2001 and currently serves as a Los Angeles-based senior correspondent.