Studies that track the dispersal of eggs and larvae from a point source are important to the emerging field of marine protected area (MPA) science. Two thousand ballasted drifter vials were released over a mutton snapper (Lutjanus analis) spawning aggregation in the Dry Tortugas, Florida, over two consecutive years (1999, 2000). The site, called Riley's Hump, is located within an MPA. The drifter vials were used as a means to model the potential dispersal and distribution of recruits originating from this site. Eleven percent of the vials were recovered each year by beachcombers. Results for each year indicated that Riley's Hump might be a source of mutton snapper recruits for a broad expanse of the Florida Keys and southeast Florida. Riley's Hump may therefore be functioning as an important fisheries reserve.