Exhibit 21 LIST OF SIGNIFICANT SUBSIDIARIES The following is a list of the significant subsidiaries of the registrant: STATE OF PERCENTAGE INCORPORATION OWNERSHIP NAME OF SIGNIFICANT SUBSIDIARY OR ORGANIZATION OF ENTITY - ------------------------------- --------------- ---------- Alton Gaming Company Illinois Corporation 100% The Missouri Gaming Company Missouri Corporation 100% The St. Louis Gaming Company Missouri Corporation 100% The Indiana Gaming Company Indiana Corporation 100% Iowa Gaming Company Iowa Corporation 100% Iowa Development Corporation Iowa Corporation 100% Argosy of Iowa, Inc. Iowa Corporation 100% Argosy of Louisiana, Inc. Louisiana Corporation 100% Jazz Enterprises, Inc. Louisiana Corporation 100% Catfish Queen Partnership In Commendam Louisiana Partnership 100% Indiana Gaming Company, L.P. Indiana Limited Partnership 57.5% Belle of Sioux City, L.P. Iowa Limited Partnership 100% Centroplex Centre Convention Hotel, L.L.C. Louisiana Limited Liability Company 100%