X0303 4 2011-05-10 0000912145 AMERISTAR CASINOS INC ASCA 0001209843 WALSH PETER 16633 VENTURA BOULEVARD SUITE 1050 ENCINO CA 91436 1 SVP, GC, Chief Admin Officer Common Stock 2011-05-10 4 M 0 10000 13.18 A 33059 I Family Trust Common Stock 2011-05-10 4 S 0 1300 22.35 D 31759 I Family Trust Common Stock 2011-05-10 4 S 0 200 22.36 D 31559 I Family Trust Common Stock 2011-05-10 4 S 0 200 22.365 D 31359 I Family Trust Common Stock 2011-05-10 4 S 0 100 22.37 D 31259 I Family Trust Common Stock 2011-05-10 4 S 0 400 22.38 D 30859 I Family Trust Common Stock 2011-05-10 4 S 0 100 22.385 D 30759 I Family Trust Common Stock 2011-05-10 4 S 0 1100 22.39 D 29659 I Family Trust Common Stock 2011-05-10 4 S 0 400 22.3925 D 29259 I Family Trust Common Stock 2011-05-10 4 S 0 733 22.3932 D 28526 I Family Trust Common Stock 2011-05-10 4 S 0 200 22.395 D 28326 I Family Trust Common Stock 2011-05-10 4 S 0 900 22.40 D 27426 I Family Trust Common Stock 2011-05-10 4 S 0 1167 22.4003 D 26259 I Family Trust Common Stock 2011-05-10 4 S 0 100 22.405 D 26159 I Family Trust Common Stock 2011-05-10 4 S 0 600 22.4075 D 25559 I Family Trust Common Stock 2011-05-10 4 S 0 400 22.415 D 25159 I Family Trust Common Stock 2011-05-10 4 S 0 100 22.42 D 25059 I Family Trust Common Stock 2011-05-10 4 S 0 500 22.43 D 24559 I Family Trust Common Stock 2011-05-10 4 S 0 500 22.45 D 24059 I Family Trust Common Stock 2011-05-10 4 S 0 200 22.455 D 23859 I Family Trust Common Stock 2011-05-10 4 S 0 500 22.46 D 23359 I Family Trust Common Stock 2011-05-10 4 S 0 300 22.47 D 23059 I Family Trust Common Stock 83028 D Stock Options (Right to Buy) 13.18 2011-05-10 4 M 0 10000 0 D 2003-04-02 2012-03-08 Common Stock 10000 197000 I Family Trust Securities owned by the Walsh Family Trust dated 9-11-03, of which Mr. Walsh and his spouse are co-trustees. Constitutes restricted stock units and performance share units, each of which represents a right to receive one share of common stock in the future. Option vested in five equal annual installments commencing on April 2, 2003. /s/ Peter C. Walsh 2011-05-11