The Sonoran Desert can be blazing hot during the day, but bone-chilling at night, especially this time of year. It's a vast, often forbidding, but spectacular place.
We spent a night roaming this area with a group of guys who form the tactical arm of the U.S. Border Patrol, called BORTAC.
These guys leave family and loved ones for seven weeks at a time to live out here in the desert. There are three shifts of about ten men apiece. The overnight shift can be the busiest, and sometimes, the toughest.
BORTAC agents are given the latest high-tech gadgets and infrared devices to track smugglers, but sometimes old-fashioned legwork and beating the brush ends up working best.
Smugglers often cross the border with large groups of illegal immigrants, sometimes 60 or even 80 in number. After crossing, they split up and try to scatter in the desert.
BORTAC agents drive along roads near the border searching for footprints and signs that groups of illegal immigrants are on the move. On our trip, I asked Russell Church, the team's leader, how he knows they won't just cross the road after we pass.
"We don't," Church said. "We just hope we can pick their tracks up the next time and pass the information on to the other agents farther north so they can flush them out."
As a routine part of their jobs, these agents will track illegal immigrants for miles through dense cactus and underbrush loaded with rattlesnakes. On the night I was with them, two agents from the overnight shift continued tracking some potential smugglers through ravines and gullies into the morning.
Around 8 a.m., three hours after their shift was over, they rounded-up 24 illegal immigrants with the help of a helicopter -- a small victory for the Border Patrol in what is shaping up to be a very large war.