X0202 4 2006-04-28 0 0001015293 HOUSTON EXPLORATION CO THX 0001234187 VAUGHN DONALD C 194 N. TRANQUIL PATH THE WOODLANDS TX 77380 1 0 0 0 common stock ($0.01 par value) 2006-04-28 4 A 0 1788 55.92 A 7788 D Common shares were granted pursuant to the Company's Amended and Restated 2004 Long-Term Incentive Plan and are restricted from sale or transfer until fully vested. Shares fully vest and restrictions are terminated at the earlier of retirement from the Houston Exploration's Board of Directors or at the end of three years from the grant date. Karol L. Adams, by Power of Attorney for Donald C. Vaughn 2006-05-02