X0306 4 2012-08-03 0000912145 AMERISTAR CASINOS INC ASCA 0001351489 Cochrane Luther P 3773 HOWARD HUGHES PKWY SUITE 490S LAS VEGAS NV 89169 1 Common Stock 2012-08-03 4 P 0 700 15.93 A 24320 D Common Stock 2012-08-03 4 P 0 100 15.94 A 24420 D Common Stock 2012-08-03 4 P 0 900 15.95 A 25320 D Common Stock 2012-08-03 4 P 0 100 15.96 A 25420 D Common Stock 2012-08-03 4 P 0 638 15.98 A 26058 D Common Stock 2012-08-03 4 P 0 1900 15.99 A 27958 D Common Stock 2012-08-03 4 P 0 8039 16.00 A 35997 D Balance includes previously reported restricted stock units, each of which constitutes the right to receive one share of common stock in the future. /s/ Peter C. Walsh, Attorney-in-Fact 2012-08-07