X0201 4 2003-12-18 0 0001166036 MARKWEST ENERGY PARTNERS L P MWE 0001235071 DENNEY ARTHUR J C/O MARKWEST ENERGY PARTNERS, L.P. 155 INVERNESS DRIVE WEST, STE 200 ENGLEWOOD CO 80112 1 1 0 0 Sr. Exec. Vice President, COO Common Units 2003-12-18 4 S 0 1000 39.90 D 3500 D Lucy Woods POA for Arthur J Denney 2003-12-19