Exhibit 21

SUBSIDIARIES OF AMERISTAR CASINOS, INC.

1. Cactus Pete's, Inc., a Nevada corporation, dba Cactus Petes Resort Casino and The Horseshu Hotel & Casino

2. Ameristar Casino Vicksburg, Inc., a Mississippi corporation

3. Ameristar Casino Council Bluffs, Inc., an Iowa corporation

4. Ameristar Casino Las Vegas, Inc., a Nevada corporation

5. Ameristar Casinos Financing Corp., a Nevada corporation

6. Ameristar Casino St. Louis, Inc., a Missouri corporation

7. Ameristar Casino St. Charles, Inc., a Missouri corporation

8. Ameristar Casino Kansas City, Inc., a Missouri corporation

9. Richmond Street Development, Inc., a Pennsylvania corporation

10. Ameristar Casino Black Hawk, Inc., a Colorado corporation

11. Ameristar East Chicago Holdings, LLC, an Indiana limited liability company

12. Ameristar Casino East Chicago, LLC, an Indiana limited liability company

13. Ameristar Casino Springfield, LLC, a Massachusetts limited liability company

14. Ameristar Lake Charles Holdings, LLC, a Louisiana limited liability company

15. Ameristar Casino Lake Charles, LLC, a Louisiana limited liability company