"We are just going to keep an eye on what's going on," said Ray Ybarra of the Arizona ACLU, which wants to be sure no illegal immigrants' civil rights are violated. The ACLU representatives carried their own radios, calling back and forth from locations around the area.
They also stood by during demonstrations by Minutemen and their supporters Saturday in Naco and in Douglas.
About 150 protesters gathered in front of the Douglas Border Patrol station chanting, "George Bush, do your job!"
Sean Pearce, a police officer from suburban Phoenix, leaned on his pickup as Lee Greenwood sang "Dixie" on his radio.
"I think all of this will put the federal government on notice as to where we stand as citizens," Pearce said.
He said that while on the job, he had been shot in the abdomen by an illegal immigrant as he executed a search warrant.
"Will this keep illegal immigrants from crossing?" he said. "Probably not."
Back on the border, the sun beat down fiercely. Simcox got on the radio and reminded everyone "to keep hydrated." Time weighed heavily as they stared out at the vast, unmoving landscape.
It would be a long month.
Lehmann was already edging more toward bird watching than immigrant spotting.
"There's that marsh hawk again," he said brightly, as the bird glided over from Mexico. "Hey, look at that butterfly. Is that a monarch? We have those in New York."