FARGO, N.D. - The roar of mammoth Air Force bombers and tanker planes has long been silenced at the Grand Forks Air Force Base, but backers of the nation's first unmanned aircraft business park say the drones are creating a buzz.

Construction on the Grand Sky grounds won't likely begin until May, but national and international companies are jockeying for position in the 1.2-million-square-foot park that sits near the former alert pad where bombers and tankers were poised for takeoff on a moment's notice.

North Dakota is one of six sites around the country testing unmanned aircraft, for which some Americans have lingering concerns about privacy and safety. The new park's tenants are likely to be researching and developing drones for a host of applications - farming, law enforcement, energy, infrastructure management, public safety, coastal security, military training, search and rescue, and disaster response. The park is expected to bring thousands of jobs to northeastern North Dakota.

Defense technology giant Northrop Grumman, based in Falls Church, Va., has already signed a letter of intent to anchor the park and more big names are likely to follow suit, Grand Sky Development president Tom Swoyer said. He added that he met with representatives from two prospective companies last week, including a "household name in the unmanned system industry" that he would not identify.

"Companies in the industry are starting to take notice," Swoyer said. "We're getting a lot of input."

One company looking to get in on the ground floor of Grand Sky is Smart C2, a fledgling software business that picked North Dakota for its home base because of the state's commitment to unmanned aircraft. Stuart Rudolph, company president and CEO, said the park will have all the key players in one space.

"Grand Sky is going to be the melting pot," Rudolph said. He noted other favorable factors, such as access to talent at the base, University of North Dakota aerospace school and a nearby technical school; government support; private equity financing; and lots of airspace.

The possibility of competitors locating under the same roof also is a good thing, Rudolph said. "This is too young of an industry to worry about your competition," he said. "We're investing in North Dakota because we think this is where the right people are going to come together to solve the problems of the United States."