X0303 4 2009-06-05 0 0001328650 Bronco Drilling Company, Inc. BRNC 0001455198 House David W C/O 16217 NORTH MAY AVENUE EDMOND OK 73013 1 0 0 0 Common Stock 2009-06-05 4 P 0 14700 6.48 A 25940 D Common Stock 2009-06-08 5 P 0 5300 6.50 A 31240 D Purchases made pursuant to previously adopted Rule 10b5-1 trading plan. Represents the weighted average price of the reporting person's acquisition of 14,700 shares on June 5, 2009 in transactions ranging from $6.34 to $6.62 per share. The reporting person undertakes to provide upon request by the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price. Represents the weighted average price of the reporting person's acquisition of 5,300 shares on June 8, 2009 in transactions ranging from $6.44 to $6.56 per share. The reporting person undertakes to provide upon request by the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price. /s/ David C. Treadwell, Attorney-in-fact 2009-06-09