Thomas F. Darden has retired from the Quicksilver Resources Inc. board chairmanship and from his officer position effective Wednesday, the company said. He will remain on the board as a director and chairman emeritus and will continue to work for Quicksilver through the end of the year. He will be focused on pursuing a joint venture in British Columbia’s Horn River Basin, something that the Fort Worth, TX-based company has sought for some time (see Shale Daily, May 8). Darden is to retire from Quicksilver on Dec. 31 but will continue to advise the company on the Horn River development and other projects, the company said. W. Yandell Rogers was elected chairman Wednesday. He has served as an independent director since March 1999.