EXHIBIT 4.20 SCHEDULE OF OPTIONS GRANTED UNDER U.S. ENERGY 2001 INCENTIVE STOCK OPTION PLAN OPTIONS GRANTED ON DECEMBER 7, 2001 AT $3.90 PER SHARE Name Number of Shares John L. Larsen 100,000 Keith G. Larsen 100,000 Daniel P. Svilar 100,000 Harold F. Herron 100,000 Mark J. Larsen 100,000 R. Scott Lorimer 100,000 Robin Kindle 100,000 Richard R. Larsen 100,000 Peter G. Schoonmaker 100,000 Robert A. Nicholas 50,000 H. Russell Fraser 20,000 Nick Bebout 20,000 Don Anderson 20,000 --------- Total 1,010,000 OPTIONS GRANTED ON MAY 20, 2002 AT $3.82 PER SHARE Name Number of Shares Bob Grabb 10,000 Karl Eppich 10,000 ------ Total 20,000