The 309th Aerospace Maintenance and Regeneration Group (309th AMARG), often called The Boneyard, is a United States Air Force aircraft and missile storage and maintenance facility in Tucson, Arizona, located on Davis–Monthan Air Force Base. The 309th AMARG was previously Aerospace Maintenance and Regeneration Center, and the Military Aircraft Storage and Disposition Center, and its predecessor was established after World War II as the 3040th Aircraft Storage Group.
The 309th AMARG takes care of nearly 4,000 aircraft, which makes it the largest aircraft storage and preservation facility in the world. An Air Force Materiel Command unit, the group is under the command of the Ogden Air Logistics Complex at Hill Air Force Base, Utah. The 309th AMARG was originally meant to store excess Department of Defense and Coast Guard aircraft, but has in recent years been designated the sole repository of out-of-service aircraft from all branches of the US government. The facility has received US made foreign military aircraft: Boeing CC-137 (from RCAF for use in Joint Stars E-8 program), Lockheed CP-140 (from RCAF). The arid climate of the region makes the 309th AMARG an ideal location for storing aircraft, as there is very little humidity in the air that would corrode metal. Further, the surface is hard so that the aircraft do not sink into the ground.