Boarman's Market on the corner of Rt 108 and Rt 216 in Highland (Howard County) will actually process deer, but they have become somewhat more restrictive since they put in a new freezer a year or two ago. As I understand it, the deer now needs to be skinned and quartered before they'll take it. I was never thrilled with their service anyway - they actually lost one of my deer once. Who knows what I wound up with...

I've been using Austin's Deer Processing in Hanover for the last couple of years, and I've been pretty happy with their service.