UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Notice of Effectiveness
Effectiveness Date: April 24, 2013 9:00 A.M.
Form: S-4
CIK: 0001346980
Company Name: Chaparral Energy, Inc.
File Number: 333-187868
CIK: 0001364760
Company Name: Chaparral Real Estate, L.L.C.
File Number: 333-187868-09
CIK: 0001364763
Company Name: Chaparral Resources, L.L.C.
File Number: 333-187868-08
CIK: 0001364759
Company Name: Chaparral CO2, L.L.C.
File Number: 333-187868-07
CIK: 0001364757
Company Name: Chaparral Energy, L.L.C.
File Number: 333-187868-06
CIK: 0001364765
Company Name: CEI Acquisition, L.L.C.
File Number: 333-187868-05
CIK: 0001382458
Company Name: CEI Pipeline, L.L.C.
File Number: 333-187868-04
CIK: 0001408822
Company Name: Green Country Supply, Inc.
File Number: 333-187868-03
CIK: 0001510108
Company Name: Chaparral Exploration, L.L.C.
File Number: 333-187868-02
CIK: 0001510109
Company Name: Roadrunner Drilling, L.L.C.
File Number: 333-187868-01