"Falcon Hill is not only Hill's future, it represents northern Utah's future," said U.S. Sen. Orrin Hatch during a news conference Wednesday minutes after the Defense Department and private developers signed a 50-year agreement to build on 550 military-owned acres east of Interstate 15.

The $1.5 billion Falcon Hill National Aerospace Research Park, whose completion is years down the road, would include facilities for Air Force personnel, as well as office parks, hotels, restaurants and shops at the base's Roy and Clearfield gates that would be open to the public.

The long-awaited project - discussion and negotiations have gone on for five years - could eventually generate more than 15,000 jobs, as well as pump half-a-billion dollars into the state's economy. Plus, it might help ensure Hill Air Force Base remains open.

"When you look at the long-term viability of the Air Force base, this is critical," said state Sen. Sheldon Killpack, R-Syracuse.

This year, the Legislature appropriated $10 million in grants for roadway changes and construction to build Falcon Hill.

The agreement, between Sunset Ridge Development Partner LLC and Hill Air Force Base, allows the private developer to finance, build on and manage the land.

The Air Force would be compensated with free use of several new buildings, as well as some lease revenue from the private office and retail buildings, said Rick Woodbury, of the Woodbury Corp., a Salt Lake City-based development partner.

Falcon Hill is the largest private-public lease partnership at an Air Force base; as of January, only four such projects had been completed, though more than two dozen are planned.

The Hill Air Force Base project is expected to take 15 years to 25 years to complete, with more than 8 million square feet of commercial space filling an area that is largely vacant save for hundreds of World War II-era facilities.

Those old buildings waste energy and are difficult to maintain, said the Air Force's project manager, Darrin Wray, and many are being vacated to be razed for the new development.

The first phase of construction is set to begin this fall and will include 2 million square feet of office and retail space, and hotels, on 180 acres largely focused at the Clearfield and Roy gates.

The fence enclosing the base would be realigned to allow public access to several office parks and shops; those businesses would generate property, sales and tourism tax that would go to the state, counties and cities. The first buildings could be completed by 2010.

mariav@sltrib.com