  We present a catalog of galaxy clusters selected using the maxBCG redsequence
method from Sloan Digital Sky Survey photometric data. This catalog includes
13,823 clusters with velocity dispersions greater than 400 km/s, and is the
largest galaxy cluster catalog assembled to date. They are selected in an
approximately volume-limited way from a 0.5 Gpc^3 region covering 7500 square
degrees of sky between redshifts 0.1 and 0.3. (ABRIGDED)
