1985 Sep 12 Ground-blessing, Observatory - summit of Maunakea, Hawaii
1988 May 25 Ground-blessing, Headquarters, Kamuela, Hawaii
1990 Nov 24 First light, Keck 1 Telescope - 9 segments installed
1991 Nov 07 Dedication of Keck 1 Telescope and Keck 2 ground-blessing
1992 Apr 14 First light, Keck 1 Telescope - 36 segments installed
1993 Mar 16 First light, NIRC instrument- decommissioned in 2010
1993 May 21 First light, LRIS instrument
1993 Jul 16 First light, HIRES instrument
1996 Jan 23 First light, Keck 2 Telescope - 24 segments installed
1996 Feb 27 First light, Keck 2 Telescope - 36 segments installed
1996 May 08 Dedication of Keck 2 Telescope
1996 Sep 30 Gerald Smith retires as WMKO Project Manager
1996 Oct 01 Dr. Frederic H. Chaffee assumes position as first Observatory Director
1998 Oct 31 First light, LWS instrument - decommissioned in 2005
1999 Feb 05 First light - Adaptive optics instrument on Keck 2 telescope
1999 Apr 25 First light, NIRSPEC instrument
1999 Aug 29 First light, ESI instrument
2000 Dec 13 First light - Adaptive optics instrument on Keck 1 telescope
2001 Jan 12 Corrected Keck 2 wavefront reaches the basement - Interferometer
2001 Mar 13 First fringes with the Keck telescopes - Interferometer
2001 Jul 29 First light, NIRC2 instrument
2001 Dec 23 First laser guide star over Maunakea created with the Keck 2 sodium laser
2002 Jun 03 First light DEIMOS instrument (DEep Imaging Multi-Object Spectrograph)
2003 Sep 09 First light for the AO LGS system (Adaptive Optics Laser Guide Star)
2005 Feb 22 First light OSIRIS instrument (OH-Suppressing Infra-Red Imaging Spectrograph)
2006 Jun 30 Dr. Frederic H. Chaffee retires as Observatory Director
2006 Jul 01 Dr. Taft Armandroff begins appointment as Observatory Director
2006 Oct 06 First light - NGWFC (Next Generation Wavefront Controller) - K1
2006 Dec 13 First Science - NIRSPAO-LGS
2007 Jan 27 First light - Cassegrain ADC for LRIS
2007 Feb 27 First light - NGWFC - K2
2009 Aug 28 First light - ASTRA dual field subsystem
2010 Jan 28 First sky propagation K1 AO LGS
2011 Jan 21 First dual-field phase referencing - ASTRA
2011 Dec Jerry Nelson named 2012 Benjamin Franklin Medal awardee in Electrical Engineering.
2012 Apr 04 First light - MOSFIRE (Multi-Object Spectrometer For Infra-Red Exploration)
2014 Sep Hilton Lewis begins appointment as Observatory Director
2017 Apr 12 First light - KCWI (Keck Cosmic Web Imager Integral Field Spectrograph)
2017 Oct 06 First light - NIRES (Near-Infrared Echellete Spectrometer)
2020 Aug 06 84th mirror segment finishes repair of glass fractures and returns to summit
2022 Nov 10 First light - KPF (Keck Planet Finder)