X0303 4 2011-02-19 0 0001060990 QUICKSILVER RESOURCES INC KWK 0001081929 DARDEN GLENN 801 CHERRY STREET SUITE 3700, UNIT 19 FORT WORTH TX 76102 1 1 0 0 President and CEO Common Stock, $.01 Par Value 2011-02-19 4 F 0 12613 15.12 D 3462593 D Common Stock, $.01 Par Value 2011-02-20 4 F 0 2002 15.12 D 3460591 D Common Stock, $.01 Par Value 41677288 I By Quicksilver Energy, L.P. Common Stock, $.01 Par Value 33590 I By 401(k) plan These shares are owned directly by Quicksilver Energy, L.P. The reporting person disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein, and this report shall not be deemed an admission that he is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. The reporting person owned 10,749.5668 units of a Unitized Stock Fund under a 401(k) plan as of February 15, 2011. Such units equate to 33,590 shares of common stock. Glenn Darden 2011-02-22