BISBEE, Ariz. — In the middle of his fourth 16-hour stretch eyeing a section of the Mexican border, Utahn Darrel Wood isn't showing any sign of fatigue.

A dirt road and a barbed-wire fence with holes big enough for a man to easily crawl through are all that separate Wood from Mexico and the source of an aggravation he has come from Price, Utah, to see for himself.

In the darkness, he waits and listens for the sound of footsteps and voices in the distance. He's out here, he says, for his seven children's education and future as part of the Minuteman Project, a monthlong effort to draw attention to illegal immigration and prove it's possible to patrol the nation's border.

Keeping watch with Wood are about 1,000 volunteers from across the United States who have signed up to monitor activity in 22 areas and report illegal crossers to the U.S. Border Patrol.

"This is not a call to arms, it's a call to action," Wood said. "My congressmen are not listening to me. This issue has been swept under the carpet for too long."

Wood says he's here because, as a Republican delegate, he's failed to convince his congressmen that illegal immigration is a critical issue. He believes the Minuteman Project has so far been a success.

Andrea Zortman, Tucson Sector Border Patrol spokeswoman, said there has been a noticeable decrease in crossing attempts and apprehensions since the project started, which is likely due to stepped up efforts by Mexican authorities.

Since March 31, 121 citizen calls have led to 282 arrests of illegal immigrants, about half the usual activity, Zortman said.

Nearby homeowners say they've seen fewer people crossing their property, and the minutemen reported a fairly quiet border. Many reported a lot of activity in the distance on the Mexico side, however, with speculation that people intending to cross were being discouraged by Grupo Beta, a Mexico human rights group.

"The border is there for a reason," Carl Meloche, of Rock Springs, Wyo., said as an orange-clad Grupo Beta member eyed his outpost from across the border.

Meloche, wearing a T-shirt with the inscription: "Some people are alive simply because it's illegal to kill them" and carrying two pistols, said he came to the border to draw attention to the fact that welfare and other social services in his hometown are being overwhelmed by illegal immigrants.

One activity has actually increased since the Minuteman Project began — the tripping of sensors along the border to detect crossers.

Zortman said the arrival of the minutemen coincides with a previously planned step-up in enforcement. For now there are about 200 additional agents detailed to Arizona, and eventually the state's Border Patrol will add 534 agents.