B-1 Bombers in storage at The Boneyard. Photo from Wikipedia.org.

TUCSON — Where to old airplanes go to die? The Boneyard.

Officially known as the 309th Aerospace Maintenance and Regeneration Center, the Boneyard is a central depot for U.S. military planes that have been taken out of service and put into storage. More than 5,000 of them now sit on 2,600 acres in the desert near Davis-Monthan Air Force Base on the outskirts of Tucson.

Some merely sit under the Arizona sun, waiting for an eventual end that may include being cannibalized for spare parts or chopped up for scrap. Others are refurbished and often sold to foreign nations, and still others are converted into drones and used as missile targets.

The planes range from old B-25 bombers to the relatively new F-14 Tomcats. Scrapped B-52s played an important role in history when the fleet was reduced to meet the terms of the SALT treaty that eased Cold War tensions. Hundreds of them were chopped into pieces by a giant guillotine and the remains were left in the open while Soviet satellites flew over and photographed them to verify destruction.

The Boneyard isn’t open to the public but the nearby Pima Air and Space Museum offers regular minibus tours.