In this photo released March 31 by Homeland Security’s Customs and Border Protection Agency is an unmanned aircraft used to monitor Red River flooding as it lands at Grand Forks, N.D., Air Force Base on Feb. 16.

Fargo, N.D. ? As the swollen Red River threatened Fargo this spring, thousands of eyes were trained on the city’s miles of sandbag walls. But just in case the townspeople missed something, the eye in the sky was watching, too.

A Predator drone of the sort used by the American military to launch missile strikes in Iraq and Afghanistan was sent up three times in recent weeks to give officials a bird’s-eye view of the floodwaters, marking the first time one of the unmanned, remote-controlled planes has been used for flood-fighting in the U.S.

Equipped with radar and infrared cameras that can see in the dark and peer through clouds, the aircraft provided remarkably detailed, real-time video images of ice floes, flood patterns and any trouble spots along the levees.

“The aerial views are extremely valuable because it’s hard to put everything in perspective when you’re looking at isolated incidents,” Mayor Dennis Walaker said this week. “If you want to look at the entire valley, the best viewpoint by far is from the air.”

The state of North Dakota asked FEMA for the use of the Predator, which is based at the Grand Forks Air Force Base and normally is employed by the U.S. Customs and Border Protection agency to scout the Canadian border for drug traffickers, illegal immigrants and terrorists.

Emergency officials long have used helicopters and small planes during disasters, but the maker of the Predator — General Atomics Aeronautical Systems Inc. — said it has distinct advantages, chief among them its ability to stay in the air for up to 30 hours.

“It’s the endurance, that’s for sure. That would be the key,” said Kimberly Kasitz, a spokeswoman for the San Diego company.

Customs spokesman Juan Munoz-Torres said some of the Predator’s sorties over North Dakota lasted 11 or 12 hours, meaning “you don’t have to stop your mission to refuel or change pilots,” as many conventional aircraft would be required to do.

And because the Predator is unmanned, no pilots had to risk their lives in bad weather. Also, the streaming video from the sky could be instantly downloaded to command centers on the ground and the laptops of people in the field.

Authorities had no immediate estimate of how much the flights over North Dakota cost. But the federal government will pick up three-quarters of the tab, with state and local officials covering the rest, said Ed Conley, a FEMA spokesman.

Such unmanned planes have been around since the mid-1990s, developed by the U.S. after the 1991 Gulf War so military commanders could view battlefields without putting pilots in danger. In recent years, missile-packing Predators have been used by the Pentagon and CIA to hunt down and kill terrorists.

The Predator used in North Dakota is about the size of a single-engine Cessna, cruises at 20,000 feet and flies at around 260 mph. A pilot at the Grand Forks air base operates it from a virtual cockpit reminiscent of an arcade game.

The aircraft can spot flood victims at night, scout dikes when it is overcast, and zoom in so close with its cameras that it can spot footprints in the snow.