  We present the first high-redshift galaxy cluster candidate sample from the
HIROCS survey found in the COSMOS field. It results from a combination of
public COSMOS with proprietary H-band data on a 0.66 square degree part of the
COSMOS field and comprises 12 candidates in the redshift range 1.23 < z < 1.55.
We find an increasing fraction of blue cluster members with increasing
redshift. Many of the blue and even some of the reddest member galaxies exhibit
disturbed morphologies as well as signs of interaction.
