W-291 must be too crowded so Lincoln went up north to W-283. There have been airspace reservations in the ZOA notams that basically extend W-283 to make it a bit bigger for the Lincoln to fly their air wing.
!CARF 07/093 ZOA AIRSPACE DCC STRIKE FIGHTER STNR ALT RESERVATION WI
AN AREA DEFINED AS 3442N12314W TO 3357N12715W TO 3410N12721W TO
3558N12405W TO POINT OF ORIGIN SFC-FL500 2107122000-2107130800