U.S. Air Force photo by Airman First Class Quentin Marx, 16FEB2021.
The military calls it ‘divestiture’, when they retire a major piece of military equipment. Under the National Defense Authorization Act, the U.S. Air Force (USAF) is required to divest 17 B-1B Lancers (aka Bones) in order to justify buying the new B-21 Raider (a new version of the B-2).
USAF photo by Airman Jonah Fronk, 17FEB2021.
On 17FEB2021, the first of several Ellisworth Air Force Base (AFB) 28th Bomb Wing ‘Bones’ was sent off on its last flight to the ‘BoneYard’ at Davis-Monthan AFB, in Arizona.
USAF photo by Airman Jonah Fronk, 16FEB2021.
On 16FEB2021, maintainers with 28th Aircraft Maintenance Squadron conducted final inspections and adjustments to #85-066.
USAF photo by Airman Jonah Fronk, 16FEB2021.
USAF photo by Airman Jonah Fronk, 16FEB2021.
USAF photo, 17FEB2021.
USAF photo, 17FEB2021.
#85-066 upon arrival at Davis-Monthan AFB, 17FEB2021.
USAF photo by Airman First Class Austin McIntosh.
The above is B-1B #85-081, photographed on 12MAR2021, also on its way to the BoneYard.
Divestiture: 
LAST FLIGHT, AND SALVATION, OF 1503
HOW TO MUMMIFY YOUR KC-10, OR, LAST FLIGHT OF 86-0036
LAST RIDE FOR 1ST, 2ND & 4TH TANK