X0303 4 2008-09-18 0 0001166036 MARKWEST ENERGY PARTNERS L P MWE 0001167209 FOX JOHN M C/O MARKWEST ENERGY PARTNERS, L.P. 1515 ARAPAHOE ST. TWR 2, STE 700 DENVER CO 80202 1 0 1 0 Common Units 2008-09-18 4 P 0 9000 22.5894 A 963014 D Common Units 6222466 I MWHC Holding, Inc. Common Units 1865 I Bode Blanco, LLC Represents purchases of 300 units at $22.37, 200 units at $22.38, 2,000 units at $22.39, 2,500 units at $22.40, 300 units at $22.73, 100 units at $22.76, 100 units at $22.78, 100 units at $22.80, 100 units at $22.82, 100 units at $22.83, and 3,200 units at $22.85. Amount of securities beneficially owned following the reported transaction(s) includes Common Units owned and Restricted Units subject to varying vesting terms. /s/ Sean M. McKendry as POA for John M. Fox 2008-09-22