X0303 4 2011-02-23 0 0001060990 QUICKSILVER RESOURCES INC KWK 0001081926 DARDEN THOMAS F 801 CHERRY STREET SUITE 3700, UNIT 19 FORT WORTH TX 76102 1 1 0 0 Chairman of the Board Common Stock, $.01 Par Value 2011-02-23 4 F 0 4458 15.30 D 3503563 D Common Stock, $.01 Par Value 1100 I By Spouse Common Stock, $.01 Par Value 41677288 I By Quicksilver Energy, L.P. Common Stock, $.01 Par Value 98760 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 31,605.3138 units of a Unitized Stock Fund under a 401(k) plan as of February 15, 2011. Such units equate to 98,760 shares of common stock. Thomas F. Darden 2011-02-25