X0303 4 2010-12-16 false 0001168054 CIMAREX ENERGY CO XEC 0001196793 HELMERICH HANS C/O CIMAREX ENERGY CO. 1700 LINCOLN STREET, SUITE 1800 DENVER CO 80203 true false false false Common Stock 2010-12-16 4 S false 1000 87.681 D 2157 I By daughter Hailey Common Stock 2010-12-16 4 S false 5000 87.74 D 36830 I Trustee, 1993 Hans Helmerich Trust Common Stock 2010-12-16 4 S false 1000 87.726 D 3140 I By Daughter Sunday Common Stock 2010-12-17 4 S false 1000 88.271 D 4545 I By Son Maxim Common Stock 2010-12-17 5 G false 1000 0 D 35830 I Trustee, 1993 Hans Helmerich Trust The price reported in Column 4 for December 16, 2010 sales is a weighted average price. These shares were sold in two transactions at $87.69 and $87.68. The reporting person undertakes to provide to Cimarex Energy Co., any security holder of Cimarex Energy Co. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. The price reported in Column 4 for December 16, 2010 sales is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.72 to $87.79, inclusive. The reporting person undertakes to provide to Cimarex Energy Co., any security holder of Cimarex Energy Co. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. The price reported in Column 4 for December 16, 2010 sales is a weighted average price. These shares were sold in multiple transactions at prices ranging from $87.71 to $87.745, inclusive. The reporting person undertakes to provide to Cimarex Energy Co., any security holder of Cimarex Energy Co. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. Thomas A. Richardson 2010-12-20