In the last twenty-five miles on the Western end of the Magdalena de Kino Road (Mexico's Federal Highway #2), the border wall frames what was once a vast sandy flat and forces it to end artificially with a straight, dark horizon line.

Surely this barrier restricts not only the view but also migration patterns of the animals living in this harsh environment.

As I passed through the border checkpoint and into San Luis, Arizona, I realized that water made all the difference for this productive area. Melon fields and farmworkers were everywhere.

Ironically, the Mexican town of Rio Colorado is named for the river that once flowed through its territory, but now the U.S. agricultural fields suck up nearly all of the mighty river's water before it reaches the border.

Is it any surprise that campesinos from Mexico must work in fields north of the border?

As I headed north on the main road to Yuma, a sign for the organization Campesinos sin Fronteras leapt into view.

I whipped the car into the parking lot and soon was talking with the organization's director, Emma Torres, mostly about SB 1070.

She invited me to an information meeting for citizens about the new bill that afternoon. Her report on the situation was dire:

"I was part of the Cesar Chavez movement," she said, "I never felt hopelessness then. Now I’m seeing despair - oppression engraved in the hearts of the young."