Seven of them were destroyed in crashes. One of those was lost in combat over Yugoslavia in 1999.

The original stealth fighter wing was based at the airfield at Tonopah Test Range inside Nellis Air Force Range, but the wing was relocated to Holloman Air Force Base, N.M., after the 1991 Persian Gulf War. The first plane arrived at Holloman in May 1992.

Fifty of the remaining F-117A Nighthawks were assigned to the 49th Fighter Wing at Holloman. Starting in December 2006, forty-six of them returned to Tonopah. The last four departed Holloman on Monday for retirement.

Of the two other remaining stealth jets, one had been assigned to a test-and-evaluation group at Nellis. The second was based at Palmdale, Calif., with the 410th Flight Test Squadron, a unit that included three preproduction models.

The first preproduction stealth jet was spared burial, repainted black and put on display at Freedom Park at Nellis Air Force Base.

The seven F-117As that crashed, aviation historians say, were the following:

•Tail No. 785, which went down April 20, 1982, during takeoff from a runway at the Groom Lake installation, known as Area 51, near the Nevada Test Site. Test pilot Robert Riedenauer suffered leg and back injuries. Equipment that controls the plane had been mistakenly reversed at Palmdale, where much of the aircraft later was converted to a display.

•Tail No. 792 crashed July 11, 1986, some 15 miles northeast of Bakersfield, Calif., during a training flight from Tonopah. The pilot, Maj. Ross Mulhare, was killed. The crash was blamed on pilot fatigue and disorientation.

•Tail No. 815 crashed Oct. 14, 1987, at Nellis Air Force Range. The pilot, Maj. Michael Stewart, was killed. The crash was caused by pilot fatigue and disorientation.

•Tail No. 801 crashed Aug. 4, 1992, at La Luz, N.M. The pilot, Capt. John Mills, ejected safely after the plane's electronic components overheated and sent it out of control.

•Tail No. 822 crashed May 10, 1995, near Zuni, N.M. The pilot, Capt. Kenneth "Buck" Levens, was killed after he became tired and disoriented and the plane flew into the ground. He made no attempt to eject.

•Tail No. 793 crashed Sept. 14, 1997, during an air show demonstration near Middle River, Md., 13 miles east of Baltimore. A wing came off the plane because some bolts were missing. The pilot, Maj. Bryan Knight, ejected safely.

•Tail No. 806 was lost in combat over Yugoslavia in March 1999 after it was hit by a surface-to-air missile. The pilot ejected safely and was rescued.