X0202 4 2007-05-21 0 0001328650 Bronco Drilling Company, Inc. BRNC 0001335995 Houston David L 16217 NORTH MAY AVENUE EDMOND OK 73013 1 0 0 0 Common Stock 2007-05-21 4 A 0 10000 A 10000 D Director Stock Option (right to buy) 17.00 2007-05-21 4 D 0 20000 D 2015-08-19 Common Stock 20000 0 D On May 21, 2007, the issuer cancelled, pursuant to the issuer?s option exchange program, an option granted to the reporting person on August 19, 2005. In exchange for the cancellation of the option, the reporting person received 10,000 shares of restricted stock granted under the Bronco Drilling Company, Inc. 2006 Stock Incentive Plan. Of these shares of restricted stock, 50% will vest on January 1, 2008 and the remaining 50% will vest on January 1, 2009. The cancelled option provided for vesting in 36 equal monthly installments beginning on August 19, 2005. /s/ David L. Houston 2007-05-23