The U.S.-Mexico Border
The Sky Islands and hummingbird sanctuaries are very close to the southern border, only a few miles away. Signs like this are common.
The border wall stretches mile after mile, as far as the eye can see.
It even slices through border towns like Naco.
The U.S. Customs and border Protection agents seem to be everywhere in their distinctive green and white SUVs.
In addition to a wall and the Border Patrol agents, there are some very sophisticated surveillance towers on the border watching for intruders. This surveillance tower has a radar and a powerful camera on top of it. First the radar sweeps the landscape to identify moving targets on the desert floor. When it finds one Border Patrol agents then use the camera to identify the target and decide whether it is worth investigating.
These surveillance towers have special meaning to me. I worked on the prototype towers in 2008 in Playas, New Mexico. Here is the tower we put up. My team was responsible for the camera and radar system at the very top. The design has changed a little since then, but I spent a lot of time in the desert working on this.
