Galaxy clusters at $z\sim1$ are particularly important in the study of cluster evolution and the application of clusters to cosmological studies. We briefly discuss the difficulties in creating well-defined, large, high-redshift cluster samples, and some of the techniques used in optical/IR imaging to overcome them. We give a summary of the current state of optical/IR observations of the relatively small number of high-redshift clusters identified so far, including discussions of the galaxy luminosity function, the Fundamental Plane, the color-magnitude relation, and the Butcher-Oemler effect. The application of photometric redshift techniques is also highlighted.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html