X0306 4 2012-11-19 0 0001166036 MARKWEST ENERGY PARTNERS L P MWE 0001227704 WOLF DONALD D C/O MARKWEST ENERGY PARTNERS, L.P. 1515 ARAPAHOE ST. TWR 1, STE. 1600 DENVER CO 80202 1 0 0 0 Common Units 58742 D Common Units 4000 I Donald D. Wolf 2007 Irrevocable Trust Common Units 4000 I Wolf Family Foundation Common Units 2012-11-19 4 P 0 1000 49.3255 A 3000 I Sharon A. Wolf Family Trust Common Units 1000 I Wolf Family Legacy Partnership, L.L.L.P. /s/ Sean M. McKendry as POA for Donald D. Wolf 2012-11-21