The Obama administration is keeping the National Guard on the U.S.-Mexico border for at least another three months, with the soldiers supporting the Border Patrol by watching for people sneaking across the border.

The soldiers act "as a critical bridge" while the administration brings new funding and personnel to the area, said Department of Homeland Security spokesman Matthew Chandler.

Last year the administration deployed 1,200 soldiers in the four border states -- California, Arizona, New Mexico and Texas -- to assist with border security. The Defense Department has now agreed to spend $35 million to extend that deployment, set to expire June 30, through the end of September.

Rancher Wendy Glenn, whose drought-stricken southern Arizona cattle ranch is edged on one side by four miles of border, said Friday she was glad to have troops posted on her property during the past year, and will welcome them back.

"They sit in a tower with radar and computers, night and day scopes, and that discourages people from trying to cross into our property," she said.

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Glenn, whose family has been ranching the land for 50 years, said she rarely sees people sneaking through her property, but she often sees their tracks and trash, and she suspects they might be responsible for recent fires.

The deployed troops are armed and trained, but their assignment is strictly hands off. Most of their work involves sitting in small turret raised about 20 feet above a truck, watching the fields and brush along the Rio Grande River. When they spot something suspicious, they call the Border Patrol to investigate.

Andrew Selee, director of the Mexico Institute at the Woodrow Wilson International Center for Scholars, said extending the deployment might make political sense amid criticism from some that the Obama Administration is neglecting border security. But the money could probably be better spent reinforcing other, more effective strategies to address the threat of organized crime in the border region, he said.

"Short-term deployments do little to enhance long-term security concerns," Selee said.

The National Guard troops have augmented the Border Patrol's 21,000 agents by almost 6 percent since July. They are credited with helping arrest 17,000 illegal immigrants, almost 6 percent of those caught, according to U.S. Customs and Border Protection. The only drug that the National Guard helped seize has been marijuana: 51,000 pounds since July -- or 2.6 percent of the almost 2 million pounds of marijuana seized by the Border Patrol during that time, said CBP.

Douglas Mayor Michael Gomez, whose city edges the Mexican border, said the National Guard helps increase security in his community.

"At first there were some complaints about having the military here," he said. "But after a while, everyone seemed to agree that they're helping."

In Columbus, New Mexico, longtime resident Martha Skinner -- whose six-room adobe inn is one of two hotels in town -- said there aren't a lot of troops in her community but they do help.

"I think having soldiers on the border makes the drug folks in Mexico a little more aware that we're protecting our borders," she said.