The Galaxy Populations of Clusters at High Redshifts: A

We present first results of a Hubble Space Telescope imaging and a Palomar and Keck Observatories spectroscopy program of distant, rich galaxy clusters in the form of a “Hubble Atlas” of morphological types at z ≥ 0.75. Two clusters from the compilation of Gunn, Hoessel & Oke (1985) have been studied to date, Cl1322+3027 at z ≈ 0.76 and Cl1603+4313 at z ≈ 0.90.