|In the section along Arizona's border with Mexico I went to examine, the barrier appears like a thin black line snaking along the desert floor below.|
Once you fix your eyes on the line, it becomes clear this is one area where building is racing ahead.
Roughly a mile of fencing is being erected every month here.
Areas of once-untouched desert are now disappearing under a lengthening slice of man-made fencing.
After setting down, we were able to get up close to the men and machines making the new fence.
Coast to coast, from the Pacific to the Gulf of Mexico, some 300 miles (500km) of barrier are completed, with another 700 miles (1100km) set to go up by the end of this year.
The fence itself is an impressive, sun-blocking, engineering feat.
Agent Jose Gonzalez of the Arizona Border Patrol tells me each 4-metre-high (13ft) panel can withstand a car impact at 45mph (70 km/h).
"It's been tested using the military's armoured vehicles," he says. "We think it will withstand pretty much any migrant car or truck."
In other places, where the terrain is more suited, electronic sensors, not walls, are being installed.
But whatever "asset" is being constructed, to use Agent Gonzalez's term, it all raises the same question of whether it will work.
"It won't stop everyone," is his honest answer.
"But we believe most migrants will be deterred".
Agent Gonzalez later drives us parallel to this gigantic metallic barrier. You can see through its grey bars. Just across the ravine inside Mexico we spot a man.
When he sees the fence and us, he changes his mind about crossing and runs off.
He is not the only one deciding he needs a plan B. In some places where the wall has been completed, and where extra border patrols are in place, illegal crossings are down by as much as 60% compared with a year ago.
The days when Mexicans, Nicaraguans, Salvadorians and others could step over flimsy strips of barbed wire to begin a new life in the US are now numbered.
Thursday, January 31, 2008
Divided views as US fence goes up
Immigration: Divided in as the people who want to jump the border and Mexican government don't like the idea.