New photometric and spectroscopic observations of galaxies in the directions of three distant clusters are presented as part of our on-going high-redshift cluster survey .
The clusters are CL1324+3011 at z = 0.76 , CL1604+4304 at z = 0.90 , and CL1604+4321 at z = 0.92 .
We have spectroscopically confirmed cluster membership for 20 to 40 galaxies in each system and have also obtained spectra for over 280 field galaxies spanning the range 0 < z < 2.5 .
Kinematic estimates of the mass within the central 770 h _ { 65 } ^ { -1 } kpc of each cluster are in excess of 8 \times 10 ^ { 14 } h _ { 65 } ^ { -1 } M _ { \odot } .
The observed x-ray luminosities in these clusters are at least a factor of 3 smaller than those observed in clusters with similar velocity dispersions at z \leq 0.4 .

These clusters contain a significant population of elliptical-like galaxies , although these galaxies are not nearly as dominant as in massive clusters at z \leq 0.5 .
We also find a large population of blue cluster members .
Defining an active galaxy as one in which the rest equivalent width of [ OII ] is greater than 15Å , the fraction of active cluster galaxies , within the central 1.0 h _ { 65 } ^ { -1 } Mpc , is 45 % .
In the field population , we find that 65 % of the galaxies with redshifts between z = 0.40 and z = 0.85 are active , while the fraction is 79 % for field galaxies at z > 0.85 .
The star formation rate normalized by the rest AB B - band magnitude , SFRN , increases as the redshift increases at a given evolving luminosity .
At a given redshift , however , SFRN decreases linearly with increasing luminosity indicating a remarkable insensitivity of the star formation rate to the intrinsic luminosity of the galaxy over the range -18 \geq { ABB } \geq - 22 .
Cluster galaxies in the central 1 h _ { 65 } ^ { -1 } Mpc regions exhibit depressed star formation rates and contain a larger fraction of galaxies with “ k ” type spectra .
The star formation rates in galaxies lying between 1 - 2.5 h _ { 65 } ^ { -1 } Mpc from the cluster centers , however , are in good agreement with that in galaxies in the general field at similar redshifts .
The spectroscopic and photometric properties of the cluster galaxies are well fit by Bruzual-Charlot solar metallicity , constant-age ( 4.8 Gyr at z = 0.9 ) , variable tau models .
Metallicities in these clusters must be at least 0.2 of solar , and a significant amount of dust extinction is unlikely .

We are able to measure significant evolution in the B -band luminosity function over the range 0.1 \leq z \leq 1 .
The characteristic luminosity increases by a factor of 3 with increasing redshift over this range .
This result is consistent with an analysis of the luminosities of the brightest cluster galaxies in these clusters .
The BCGs are typically twice as luminous as their current epoch counterparts .