System and method for storing a dataset of image tiles. Method includes determining a number of zoom levels, accessing a cluster file that includes a subset of the zoom levels, and accessing the image tiles. For each of the image tiles, a cluster name is computed. For each of the image tiles, if the cluster file has a name that matches the computed cluster name, an image tile pointer is stored in a fixed length index, and the image tile associated with the computed cluster name is stored. For each of the image tiles, if the cluster file name does not match the computed cluster name, another subset of the zoom levels is computed, a new cluster file is created, an image tile pointer is created and stored, and the image tile is stored associated with the computed cluster name in the new cluster file according to the image tile pointer.