X0303 4 2009-07-31 0000912145 AMERISTAR CASINOS INC ASCA 0001367395 Rollo Heather A 3773 HOWARD HUGHES PKWY SUITE 490S LAS VEGAS NV 89169 1 Chief Accounting Officer Common Stock 2009-07-31 4 A 0 3740 0 A 16740 D Stock Options (Right to Buy) 18.62 2009-07-31 4 A 0 2900 0 A 2010-07-30 2019-07-31 Common Stock 2900 2900 D Constitutes a grant of restricted stock units, each of which represents a right to receive one share of common stock in the future. Such restricted stock units vest in four equal, annual installments commencing on July 30, 2010. Balance includes previously reported restricted stock units, each of which constitutes the right to receive one share of common stock in the future. Options vest in four equal, annual installments commencing on July 30, 2010. /s/ Heather A. Rollo 2009-08-04