X0202 4 2004-05-19 0 0000824142 AAON INC AAON 0000903063 ASBJORNSON NORMAN H AAON INC 2425 SOUTH YUKON TULSA OK 74107 1 1 1 0 President Common Stock, par value $.004 2004-05-19 2004-05-19 4 S 0 100 19.7 D 2235208 D Common Stock, par value $.004 2004-05-19 2004-05-19 4 S 0 300 19.71 D 2234908 D Common Stock, par value $.004 2004-05-20 2004-05-20 4 S 0 145 19.7 D 2234763 D Common Stock, par value $.004 4500 I Private Foundation Common Stock, par value $.004 7956 I 401(k) Plan Common Stock, par value $.004 11062 I IRA Account Plan B Stock Option 2.33 1998-01-08 2007-01-08 Common Stock 67500 67500 D Stock Option 3.19 1998-03-11 2007-03-11 Common Stock 61875 61875 D Stock Option 3.39 1999-01-16 2008-01-16 Common Stock 45000 45000 D Stock Option 4 1999-12-28 2008-12-28 Common Stock 112500 112500 D Stock Option 5.78 2000-10-13 2009-10-13 Common Stock 11250 11250 D Adjusted for interim stock split and contributions. Adjusted for interim stock split. /s/ Norman H. Asbjornson 2004-05-20